A part comes back from the first article inspection with a visible dimple on an otherwise clean surface. The engineer who designed it is confused, because the wall in question was made thicker on purpose, specifically to add strength at a stress point the part sees in service. The added material was supposed to be a safety margin. Instead it produced the exact defect the design was trying to avoid.
This happens often enough that it is worth asking why. The answer is that wall thickness in injection molding runs on a set of rules that sound intuitive and are frequently wrong. Below are five of the most common ones, and what the physics actually says.
A strong and corrosion-resistant material commonly used for CNC machining parts like precision components, medical instruments, and automotive components.
A durable thermoplastic material suitable for CNC machining complex parts like gears, bearings, and bushings, known for its excellent dimensional stability and low friction properties.
A versatile engineering plastic widely used for CNC machining components such as precision gears, rollers, and valve bodies due to its low friction, high strength, and dimensional stability.
An impact-resistant and transparent material often CNC machined into parts like safety goggles, electronic enclosures, and automotive lighting covers due to its excellent strength and optical clarity.
A strong and flexible material used for CNC machining parts like gears, pulleys, and bearings due to its high wear resistance, low friction, and excellent mechanical properties.
A durable and impact-resistant thermoplastic commonly CNC machined into parts like prototypes, enclosures, and consumer goods due to its good mechanical properties, ease of machining, and wide range of available colors.
A metal alloy known for its excellent machinability and corrosion resistance, often CNC machined into parts like fittings, valves, and decorative components due to its aesthetic appeal and durability.
A highly conductive and malleable material often CNC machined into electrical connectors, heat sinks, and RF shields due to its excellent electrical and thermal properties.
A low-carbon steel commonly CNC machined into parts like brackets, shafts, and structural components due to its strength, machinability, and cost-effectiveness.
A lightweight and versatile material used for CNC machining applications like packaging inserts, architectural models, and signage due to its ease of machining, low density, and impact-absorbing properties.
A high-performance engineering plastic known for its excellent dimensional stability, low friction, and high wear resistance, often CNC machined into parts like bushings, gears, and bearings.
A strong and corrosion-resistant material commonly used for CNC machining parts like precision components, medical instruments, and automotive components.
A durable thermoplastic material suitable for CNC machining complex parts like gears, bearings, and bushings, known for its excellent dimensional stability and low friction properties.
A versatile engineering plastic widely used for CNC machining components such as precision gears, rollers, and valve bodies due to its low friction, high strength, and dimensional stability.
An impact-resistant and transparent material often CNC machined into parts like safety goggles, electronic enclosures, and automotive lighting covers due to its excellent strength and optical clarity.
A strong and flexible material used for CNC machining parts like gears, pulleys, and bearings due to its high wear resistance, low friction, and excellent mechanical properties.
A durable and impact-resistant thermoplastic commonly CNC machined into parts like prototypes, enclosures, and consumer goods due to its good mechanical properties, ease of machining, and wide range of available colors.
A metal alloy known for its excellent machinability and corrosion resistance, often CNC machined into parts like fittings, valves, and decorative components due to its aesthetic appeal and durability.
A highly conductive and malleable material often CNC machined into electrical connectors, heat sinks, and RF shields due to its excellent electrical and thermal properties.
A low-carbon steel commonly CNC machined into parts like brackets, shafts, and structural components due to its strength, machinability, and cost-effectiveness.
A lightweight and versatile material used for CNC machining applications like packaging inserts, architectural models, and signage due to its ease of machining, low density, and impact-absorbing properties.
A high-performance engineering plastic known for its excellent dimensional stability, low friction, and high wear resistance, often CNC machined into parts like bushings, gears, and bearings.
| Material | Mechanical Properties | Physical Properties | Chemical Properties | Features | Common Applications |
|---|---|---|---|---|---|
|
Tensile Strength: 60-70 MPa Impact Strength: 10-20 kJ/m² Heat Deflection Temperature: 135-150°C |
Transparent or translucent Good dimensional stability |
Resistant to many chemicals and oils
|
Excellent transparency High temperature resistance |
Aerospace and Defense: Transparent canopies, Medical: Medical device components |
|
|
Tensile Strength: 40-60 MPa Impact Strength: 5-20 kJ/m² Heat Deflection Temperature: 100-120°C |
Various colors available Good dimensional stability |
Resistant to many chemicals and oils
|
Suitable for high-temperature applications |
Aerospace and Defense: Engine components, Automotive: Engine components |
|
|
Tensile Strength: 60-80 MPa Impact Strength: 20-40 kJ/m² Density: 1.03 g/cm³ Melting Point: 220-260°C |
Various colors available Low density Good dimensional stability |
Resistant to many chemicals and oils
|
High strength and impact resistance Lightweight |
Automotive: Bumpers, Aerospace and Defense: Structural components |
|
|
Tensile Strength: 40-60 MPa Impact Strength: 5-20 kJ/m² Density: 1.03 g/cm³ Melting Point: 220-260°C |
Black color Low density Good dimensional stability |
Resistant to many chemicals and oils
|
Black appearance
Lightweight – Durable |
Consumer Products: Electronics casings, automotive interior parts |
|
|
Tensile Strength: 40-60 MPa Impact Strength: 5-20 kJ/m² Density: 1.03 g/cm³ Melting Point: 220-260°C |
White color Low density Good dimensional stability |
Resistant to many chemicals and oils
|
White appearance
Lightweight Durable |
Consumer Products: Electronics casings, toys, kitchen appliances |
|
|
ABS |
Good impact resistance |
Density: 1.03 g/cm³ |
Resistant to diluted acids, alkalis |
High strength, versatility,
cost-effective |
Automotive, Consumer Products |
|
ABS – M30i |
– Good tensile strength |
– Density: 1.04 g/cm³ |
– Medical grade |
– Biocompatible, sterilizable, suitable for medical devices |
Medical |
|
ABS ESD |
– Static-dissipative properties |
– Density: 1.06 g/cm³ |
– ESD protection |
– Prevents electrostatic discharge, suitable for electronics |
Aerospace and Defense, Consumer Products |
|
ABS-Like |
– High toughness and durability |
– Density: Varies by formulation |
– Resistant to various chemicals |
– Resembles ABS but may offer specific improvements |
Varies by formulation |
|
Accura 25 |
– High accuracy and resolution |
– Density: Varies by formulation |
– Photopolymer |
– Used in stereolithography 3D printing, fine details |
Consumer Products, Medical, Aerospace and Defense |
|
Accura 60 |
– High strength and durability |
– Density: Varies by formulation |
– Photopolymer |
– Tough and durable, suitable for functional prototypes |
Consumer Products, Aerospace and Defense |
|
Accura AMX Rigid Black |
– High impact resistance |
– Density: Varies by formulation |
– Photopolymer |
– Rigid and durable, good for functional prototypes |
Consumer Products, Aerospace and Defense |
|
Accura ClearVue |
– High transparency and clarity |
– Density: Varies by formulation |
– Photopolymer |
– Crystal clear appearance, ideal for clear parts |
Consumer Products, Medical |
|
Accura Xtreme Grey/White |
– High toughness and durability |
– Density: Varies by formulation |
– Photopolymer |
– Resistant to high temperatures, strong and rigid |
Consumer Products, Aerospace and Defense |
|
ASA |
– Excellent UV resistance |
– Density: 1.07 g/cm³ |
– Weather-resistant |
– Outdoor durability, retains color and strength in sunlight |
Automotive, Consumer Products |
|
Nylon |
– High tensile strength |
– Density: 1.15 g/cm³ |
– Resistant to moisture, chemicals |
– Tough and durable, suitable for functional parts |
Aerospace and Defense, Automotive, Consumer Products |
|
Nylon 11 Flame Retardant |
– Flame retardant properties |
– Density: Varies by formulation |
– Flame-resistant |
– Fire safety, suitable for applications requiring flame resistance |
Aerospace and Defense, Automotive |
|
Nylon 12 |
– Good chemical resistance |
– Density: 1.02 g/cm³ |
– Resistant to oils, greases |
– Versatile, suitable for various industrial applications |
Aerospace and Defense, Automotive, Consumer Products, Oil and Gas |
|
Nylon 6 |
– High impact strength |
– Density: 1.14 g/cm³ |
– Resistant to moisture, abrasion |
– Durable, excellent for applications requiring impact resistance |
Automotive, Consumer Products |
|
PA 12 Glass Beads |
– Improved stiffness and dimensional stability |
– Density: Varies by formulation |
– Reinforced with glass beads |
– Increased stiffness, suitable for engineering applications |
Automotive, Aerospace and Defense |
|
PC-ISO |
– High strength and heat resistance |
– Density: Varies by formulation |
– Biocompatible |
– Suitable for medical and aerospace applications |
Aerospace and Defense, Medical |
|
PC+ABS |
– Good impact resistance |
– Density: Varies by formulation |
– Resistant to chemicals |
– Blends properties of PC and ABS, versatile material |
Automotive, Consumer Products |
|
PETG |
– Excellent transparency and impact resistance |
– Density: 1.27 g/cm³ |
– Food-safe, BPA-free |
– Clarity and toughness, ideal for packaging and displays |
Consumer Products, Medical |
|
PLA |
– Biodegradable and easy to print |
– Density: 1.24 g/cm³ |
– Biodegradable |
– Eco-friendly, easy to 3D print |
Consumer Products, Medical |
|
Polycarbonate (PC) |
– High impact resistance, optical clarity |
– Density: 1.20 g/cm³ |
– Excellent optical properties |
– Exceptional clarity and strength, suitable for transparent parts |
Aerospace and Defense, Consumer Products, Medical |
|
Polypropylene |
– Low density and good chemical resistance |
– Density: 0.90 g/cm³ |
– Resistant to moisture, chemicals |
– Lightweight, suitable for low-stress applications |
Consumer Products, Automotive |
|
Rubber-Like |
– Flexible and rubber-like properties |
– Density: Varies by formulation |
– Flexible elastomer |
– Mimics rubber, suitable for gaskets and seals |
Automotive, Consumer Products |
|
Somos Evolve |
– High strength and heat resistance |
– Density: Varies by formulation |
– Photopolymer |
– Engineering-grade material, suitable for functional prototypes |
Aerospace and Defense, Automotive |
|
Somos PerFORM |
– High stiffness and heat resistance |
– Density: Varies by formulation |
– Photopolymer |
– Strong and stiff, ideal for high-temperature applications |
Aerospace and Defense |
|
Somos Waterclear |
– High transparency and clarity |
– Density: Varies by formulation |
– Photopolymer |
– Transparent, suitable for clear prototypes and parts |
Consumer Products, Medical |
|
Somos Watershed |
– Excellent clarity and water resistance |
– Density: Varies by formulation |
– Photopolymer |
– Waterproof, suitable for water-resistant parts |
Consumer Products, Medical |
|
ST-130 |
– High toughness and durability |
– Density: Varies by formulation |
– Photopolymer |
– Rigid, tough, and durable, good for functional prototypes |
Consumer Products, Aerospace and Defense |
|
TPU 88A |
– Flexible and elastomeric properties |
– Density: Varies by formulation |
– Thermoplastic polyurethane |
– Flexibility and resilience, suitable for elastomeric parts |
Automotive, Consumer Products, Medical |
|
Ultem 1010 |
– High strength, heat, and chemical resistance |
– Density: 1.27 g/cm³ |
– Flame-resistant, UL 94 V0 |
– Engineering-grade thermoplastic with excellent properties |
Aerospace and Defense, Automotive, Oil and Gas |
|
Ultem 9085 |
– High strength, heat, and chemical resistance |
– Density: 1.27 g/cm³ |
– Flame-resistant, UL 94 V0 |
– Suitable for aerospace and transportation applications |
Aerospace and Defense, Automotive |
|
Vero |
– Rigid and durable |
– Density: Varies by formulation |
– Photopolymer |
– Versatile material, good for prototypes and models |
Consumer Products, Aerospace and Defense |
|
VeroClear |
– High transparency and clarity |
– Density: Varies by formulation |
– Photopolymer |
– Transparent appearance, ideal for clear parts |
Consumer Products, Medical |
This gets treated as a strict rule, and it is not. What actually matters is that thickness changes gradually rather than abruptly. The commonly used guideline allows a wall to run as low as 40 to 60 percent of the thickness of an adjacent wall without causing problems, as long as the transition between them is tapered rather than a hard step. What causes defects is not variation itself, it is an abrupt jump from thick to thin, which cools unevenly and shows up as warping or a visible flow line at the transition point.
This is the myth behind the dimple in the opening story, and it is the most expensive one on this list. When a thick section cools, the outer surface solidifies first while the material underneath is still molten. As that interior cools and shrinks afterward, it pulls the outer skin inward, which is what produces a sink mark. In more severe cases, the same shrinkage forms an internal void that never shows up visually but weakens the part exactly where the extra material was added to strengthen it.
What we are seeing across programs at PrintForm is that ribs solve the strength problem that thick walls were meant to solve, without the thermal penalty. A rib adds stiffness in a specific direction without creating a thick mass that has to cool from the outside in, and it uses less material to do it.
A well-placed rib almost always outperforms a thicker wall, at a lower material and cycle cost.
This one comes from a reasonable instinct that more material means more strength, and it fails for the same reason Myth 2 does. A rib built at 80 to 100 percent of the nominal wall thickness behaves like a thick wall at its base, and produces the same sink mark on the opposite surface. The functional range that avoids this is 40 to 60 percent of the adjacent wall, with some allowance up to 70 percent for glass filled materials, which shrink less during cooling. Past that range, a thicker rib is not adding meaningful stiffness, it is just adding a defect risk in a feature meant to prevent one.
This shows up constantly in early concept discussions, usually as a flat number pulled from a previous project. There is no such number. Minimum and maximum wall thickness both depend on the specific resin, its shrinkage behavior, the part’s flow length, and what the feature needs to do structurally. A minimum thickness that works for an ABS housing is not the same minimum that works for a glass filled nylon bracket, and treating either as a universal default is how a part ends up either too thin to fill completely or thick enough to trigger the problems in Myth 2.
The right number depends on resin, flow length, and function, not a number from a past project.
Material is the smaller cost. The bigger driver is cycle time, and it scales badly. Thicker sections take longer to cool before a part can be safely ejected, and that cooling time does not increase in a straight line with thickness, it increases with the square of it. In practical terms, going from a 2mm wall to a 3mm wall can roughly double the per-part manufacturing cost through cooling time alone, well before material usage is even factored in. On a high volume production run, that difference compounds across every single cycle, all day, for the life of the program.
Every one of these assumptions made sense at some point, usually on a part where the geometry, material, or volume happened to make the shortcut work. The problem is that the shortcut gets carried forward as a rule rather than a case-specific result, and it resurfaces on a program where the resin, wall depth, or production volume no longer supports it. A rib ratio that was fine on one material is a sink mark risk on another. A wall thickness that worked at low volume becomes a real cycle time cost once a program scales into the hundreds of thousands of units. This is the same pattern that shows up in draft angle design, where the correct answer also depends on the specific wall, texture, and material rather than a fixed default.
PrintForm's team reviews wall thickness, rib ratios, and cooling time against your actual material and volume before the quote is final, not after the first sink mark shows up.
A strong and corrosion-resistant material commonly used for CNC machining parts like precision components, medical instruments, and automotive components.
A durable thermoplastic material suitable for CNC machining complex parts like gears, bearings, and bushings, known for its excellent dimensional stability and low friction properties.
A versatile engineering plastic widely used for CNC machining components such as precision gears, rollers, and valve bodies due to its low friction, high strength, and dimensional stability.
An impact-resistant and transparent material often CNC machined into parts like safety goggles, electronic enclosures, and automotive lighting covers due to its excellent strength and optical clarity.
A strong and flexible material used for CNC machining parts like gears, pulleys, and bearings due to its high wear resistance, low friction, and excellent mechanical properties.
A durable and impact-resistant thermoplastic commonly CNC machined into parts like prototypes, enclosures, and consumer goods due to its good mechanical properties, ease of machining, and wide range of available colors.
A metal alloy known for its excellent machinability and corrosion resistance, often CNC machined into parts like fittings, valves, and decorative components due to its aesthetic appeal and durability.
A highly conductive and malleable material often CNC machined into electrical connectors, heat sinks, and RF shields due to its excellent electrical and thermal properties.
A low-carbon steel commonly CNC machined into parts like brackets, shafts, and structural components due to its strength, machinability, and cost-effectiveness.
A lightweight and versatile material used for CNC machining applications like packaging inserts, architectural models, and signage due to its ease of machining, low density, and impact-absorbing properties.
A high-performance engineering plastic known for its excellent dimensional stability, low friction, and high wear resistance, often CNC machined into parts like bushings, gears, and bearings.
A strong and corrosion-resistant material commonly used for CNC machining parts like precision components, medical instruments, and automotive components.
A durable thermoplastic material suitable for CNC machining complex parts like gears, bearings, and bushings, known for its excellent dimensional stability and low friction properties.
A versatile engineering plastic widely used for CNC machining components such as precision gears, rollers, and valve bodies due to its low friction, high strength, and dimensional stability.
An impact-resistant and transparent material often CNC machined into parts like safety goggles, electronic enclosures, and automotive lighting covers due to its excellent strength and optical clarity.
A strong and flexible material used for CNC machining parts like gears, pulleys, and bearings due to its high wear resistance, low friction, and excellent mechanical properties.
A durable and impact-resistant thermoplastic commonly CNC machined into parts like prototypes, enclosures, and consumer goods due to its good mechanical properties, ease of machining, and wide range of available colors.
A metal alloy known for its excellent machinability and corrosion resistance, often CNC machined into parts like fittings, valves, and decorative components due to its aesthetic appeal and durability.
A highly conductive and malleable material often CNC machined into electrical connectors, heat sinks, and RF shields due to its excellent electrical and thermal properties.
A low-carbon steel commonly CNC machined into parts like brackets, shafts, and structural components due to its strength, machinability, and cost-effectiveness.
A lightweight and versatile material used for CNC machining applications like packaging inserts, architectural models, and signage due to its ease of machining, low density, and impact-absorbing properties.
A high-performance engineering plastic known for its excellent dimensional stability, low friction, and high wear resistance, often CNC machined into parts like bushings, gears, and bearings.
| Material | Mechanical Properties | Physical Properties | Chemical Properties | Features | Common Applications |
|---|---|---|---|---|---|
|
Tensile Strength: 60-70 MPa Impact Strength: 10-20 kJ/m² Heat Deflection Temperature: 135-150°C |
Transparent or translucent Good dimensional stability |
Resistant to many chemicals and oils
|
Excellent transparency High temperature resistance |
Aerospace and Defense: Transparent canopies, Medical: Medical device components |
|
|
Tensile Strength: 40-60 MPa Impact Strength: 5-20 kJ/m² Heat Deflection Temperature: 100-120°C |
Various colors available Good dimensional stability |
Resistant to many chemicals and oils
|
Suitable for high-temperature applications |
Aerospace and Defense: Engine components, Automotive: Engine components |
|
|
Tensile Strength: 60-80 MPa Impact Strength: 20-40 kJ/m² Density: 1.03 g/cm³ Melting Point: 220-260°C |
Various colors available Low density Good dimensional stability |
Resistant to many chemicals and oils
|
High strength and impact resistance Lightweight |
Automotive: Bumpers, Aerospace and Defense: Structural components |
|
|
Tensile Strength: 40-60 MPa Impact Strength: 5-20 kJ/m² Density: 1.03 g/cm³ Melting Point: 220-260°C |
Black color Low density Good dimensional stability |
Resistant to many chemicals and oils
|
Black appearance
Lightweight – Durable |
Consumer Products: Electronics casings, automotive interior parts |
|
|
Tensile Strength: 40-60 MPa Impact Strength: 5-20 kJ/m² Density: 1.03 g/cm³ Melting Point: 220-260°C |
White color Low density Good dimensional stability |
Resistant to many chemicals and oils
|
White appearance
Lightweight Durable |
Consumer Products: Electronics casings, toys, kitchen appliances |
|
|
ABS |
Good impact resistance |
Density: 1.03 g/cm³ |
Resistant to diluted acids, alkalis |
High strength, versatility,
cost-effective |
Automotive, Consumer Products |
|
ABS – M30i |
– Good tensile strength |
– Density: 1.04 g/cm³ |
– Medical grade |
– Biocompatible, sterilizable, suitable for medical devices |
Medical |
|
ABS ESD |
– Static-dissipative properties |
– Density: 1.06 g/cm³ |
– ESD protection |
– Prevents electrostatic discharge, suitable for electronics |
Aerospace and Defense, Consumer Products |
|
ABS-Like |
– High toughness and durability |
– Density: Varies by formulation |
– Resistant to various chemicals |
– Resembles ABS but may offer specific improvements |
Varies by formulation |
|
Accura 25 |
– High accuracy and resolution |
– Density: Varies by formulation |
– Photopolymer |
– Used in stereolithography 3D printing, fine details |
Consumer Products, Medical, Aerospace and Defense |
|
Accura 60 |
– High strength and durability |
– Density: Varies by formulation |
– Photopolymer |
– Tough and durable, suitable for functional prototypes |
Consumer Products, Aerospace and Defense |
|
Accura AMX Rigid Black |
– High impact resistance |
– Density: Varies by formulation |
– Photopolymer |
– Rigid and durable, good for functional prototypes |
Consumer Products, Aerospace and Defense |
|
Accura ClearVue |
– High transparency and clarity |
– Density: Varies by formulation |
– Photopolymer |
– Crystal clear appearance, ideal for clear parts |
Consumer Products, Medical |
|
Accura Xtreme Grey/White |
– High toughness and durability |
– Density: Varies by formulation |
– Photopolymer |
– Resistant to high temperatures, strong and rigid |
Consumer Products, Aerospace and Defense |
|
ASA |
– Excellent UV resistance |
– Density: 1.07 g/cm³ |
– Weather-resistant |
– Outdoor durability, retains color and strength in sunlight |
Automotive, Consumer Products |
|
Nylon |
– High tensile strength |
– Density: 1.15 g/cm³ |
– Resistant to moisture, chemicals |
– Tough and durable, suitable for functional parts |
Aerospace and Defense, Automotive, Consumer Products |
|
Nylon 11 Flame Retardant |
– Flame retardant properties |
– Density: Varies by formulation |
– Flame-resistant |
– Fire safety, suitable for applications requiring flame resistance |
Aerospace and Defense, Automotive |
|
Nylon 12 |
– Good chemical resistance |
– Density: 1.02 g/cm³ |
– Resistant to oils, greases |
– Versatile, suitable for various industrial applications |
Aerospace and Defense, Automotive, Consumer Products, Oil and Gas |
|
Nylon 6 |
– High impact strength |
– Density: 1.14 g/cm³ |
– Resistant to moisture, abrasion |
– Durable, excellent for applications requiring impact resistance |
Automotive, Consumer Products |
|
PA 12 Glass Beads |
– Improved stiffness and dimensional stability |
– Density: Varies by formulation |
– Reinforced with glass beads |
– Increased stiffness, suitable for engineering applications |
Automotive, Aerospace and Defense |
|
PC-ISO |
– High strength and heat resistance |
– Density: Varies by formulation |
– Biocompatible |
– Suitable for medical and aerospace applications |
Aerospace and Defense, Medical |
|
PC+ABS |
– Good impact resistance |
– Density: Varies by formulation |
– Resistant to chemicals |
– Blends properties of PC and ABS, versatile material |
Automotive, Consumer Products |
|
PETG |
– Excellent transparency and impact resistance |
– Density: 1.27 g/cm³ |
– Food-safe, BPA-free |
– Clarity and toughness, ideal for packaging and displays |
Consumer Products, Medical |
|
PLA |
– Biodegradable and easy to print |
– Density: 1.24 g/cm³ |
– Biodegradable |
– Eco-friendly, easy to 3D print |
Consumer Products, Medical |
|
Polycarbonate (PC) |
– High impact resistance, optical clarity |
– Density: 1.20 g/cm³ |
– Excellent optical properties |
– Exceptional clarity and strength, suitable for transparent parts |
Aerospace and Defense, Consumer Products, Medical |
|
Polypropylene |
– Low density and good chemical resistance |
– Density: 0.90 g/cm³ |
– Resistant to moisture, chemicals |
– Lightweight, suitable for low-stress applications |
Consumer Products, Automotive |
|
Rubber-Like |
– Flexible and rubber-like properties |
– Density: Varies by formulation |
– Flexible elastomer |
– Mimics rubber, suitable for gaskets and seals |
Automotive, Consumer Products |
|
Somos Evolve |
– High strength and heat resistance |
– Density: Varies by formulation |
– Photopolymer |
– Engineering-grade material, suitable for functional prototypes |
Aerospace and Defense, Automotive |
|
Somos PerFORM |
– High stiffness and heat resistance |
– Density: Varies by formulation |
– Photopolymer |
– Strong and stiff, ideal for high-temperature applications |
Aerospace and Defense |
|
Somos Waterclear |
– High transparency and clarity |
– Density: Varies by formulation |
– Photopolymer |
– Transparent, suitable for clear prototypes and parts |
Consumer Products, Medical |
|
Somos Watershed |
– Excellent clarity and water resistance |
– Density: Varies by formulation |
– Photopolymer |
– Waterproof, suitable for water-resistant parts |
Consumer Products, Medical |
|
ST-130 |
– High toughness and durability |
– Density: Varies by formulation |
– Photopolymer |
– Rigid, tough, and durable, good for functional prototypes |
Consumer Products, Aerospace and Defense |
|
TPU 88A |
– Flexible and elastomeric properties |
– Density: Varies by formulation |
– Thermoplastic polyurethane |
– Flexibility and resilience, suitable for elastomeric parts |
Automotive, Consumer Products, Medical |
|
Ultem 1010 |
– High strength, heat, and chemical resistance |
– Density: 1.27 g/cm³ |
– Flame-resistant, UL 94 V0 |
– Engineering-grade thermoplastic with excellent properties |
Aerospace and Defense, Automotive, Oil and Gas |
|
Ultem 9085 |
– High strength, heat, and chemical resistance |
– Density: 1.27 g/cm³ |
– Flame-resistant, UL 94 V0 |
– Suitable for aerospace and transportation applications |
Aerospace and Defense, Automotive |
|
Vero |
– Rigid and durable |
– Density: Varies by formulation |
– Photopolymer |
– Versatile material, good for prototypes and models |
Consumer Products, Aerospace and Defense |
|
VeroClear |
– High transparency and clarity |
– Density: Varies by formulation |
– Photopolymer |
– Transparent appearance, ideal for clear parts |
Consumer Products, Medical |
Geometry is where CNC Machining and Injection Molding stop looking like two versions of the same decision and start looking like two completely different sets of rules.
Most process decisions do not go wrong because someone picked the wrong process. They go wrong because no one asked the right questions before the design was locked and the quote was requested.
Surface finish is where a lot of engineers get surprised by their first quote. A part that looks perfect in a CAD render does not automatically come out of either process looking that way, and the path to a true cosmetic finish is completely different depending on whether the part is machined or molded.
Tolerance is usually the first question engineers ask when comparing CNC Machining and Injection Molding, and it is also the question most likely to get a vague answer.
CNC Machining and Injection Molding are the two most requested manufacturing processes for custom parts, and the two most confused. Engineers often default to whichever one they used last, instead of the one their part actually needs. The right choice comes down to seven factors.
A part comes back from the first article inspection with a visible dimple on an otherwise clean surface. The engineer who designed it is confused, because the wall in question was made thicker on purpose, specifically to add strength at a stress point the part sees in service.
A part comes off the line and the operator has to stop the press, pry the part loose by hand, and check the mold for scuffing before the next cycle can run. Nobody changed the material.
An engineer sends a CAD file out for quote. Three days later the file comes back with five DFM comments attached. Four of them get a quick “noted, proceeding as is.” The fifth gets a one line reply: we have built parts like this before.
The program was behind schedule. The tooling brief was ready. The team had run the part in ABS before with the same wall structure, similar geometry, nothing exotic.
An automotive supplier had been producing mirror housings without issue for two years. When a new program required a cosmetic grade paint finish, the weld line that had always been present, invisible under the original texture, became a visible seam running straight across the primary Class A surface.
The mold arrived from the toolmaker on a Thursday. T1 shots were running by Friday afternoon. By Monday morning, the program manager had three problems: the housing was warping 0.8mm out of flat, a critical mating boss was 0.35mm undersized, and a cosmetic weld line was running directly through the logo face.
The bracket passed CAD review three times. Wall thickness was uniform on paper, tolerances were realistic, and the design team had done everything a checklist would ask of them.
The enclosure design cleared every functional test. Material was strong. Dimensions were right. Cosmetic finish was approved. At 500 units, the per-part cost was $4.20, within budget.
The program’s financial model had scrap at 3%. Supplier quoted 3%. Everyone agreed: 3%.
Eighteen months into production, actual scrap was running at 9.2%.
A defense contractor’s thermal management pads arrived dimensionally perfect.
The procurement team had three quotes on the table. They ranged from $0.58 to $0.91 per part at 50,000 units annually. The team chose the lowest.
Here is a pattern we see more often than we should. A program reaches production readiness, design is locked, tooling is ordered or already in-house, the supply chain is set.
An industrial equipment manufacturer came to us with an enclosure design that had been developed on solid modeling software by an engineer whose previous experience was almost entirely in machined components.
A product team was twelve weeks from a clinical submission deadline. They needed thirty units of a handheld medical device housing, production-representative in cosmetics, dimensionally accurate, and available in two colorways for user testing.
A consumer electronics company came to us with a housing part they had been machining at low volume while they waited on market validation.
Picture a part that has been through weeks of engineering review. The 3D model is solid. Wall thicknesses have been checked, tolerances have been assigned, and the geometry looks exactly the way it needs to function.
The quote came in at $12,000. The domestic option was $49,000. For a medical device manufacturer under budget pressure, the math looked obvious – until the tool arrived.
The product manager’s spreadsheet said injection molding was cheaper. It was – on a per-part basis. What the spreadsheet didn’t include was the $18,000 steel mold, the six-week lead time.
The design passed DVT. The contract manufacturer had been briefed. The steel mold was quoted. And then someone on the leadership team asked when they could start shipping.
The part passed every test. Eight months of iteration, four rounds of DVT, a signed-off design review. The first production run shipped 400 units. Thirty percent came back.
The medical device startup had 60 days to get functional housings into the hands of a clinical partner. Their enclosure design was largely validated – one or two minor tweaks still possible, but nothing structural.
A product manager at a consumer electronics company recently landed a pilot order: 1,200 units of a plastic enclosure, confirmed purchase order, ship date in eight weeks.
A medical device company completes a successful pilot. The manufacturing process looks clean, the assembly line is humming, and the launch timeline is on track – until field returns start coming in at month four.
The engineering team celebrated. Their medical device prototype worked perfectly, passed initial testing, and impressed investors. Early manufacturing decisions looked solid.
The product manager had 72 hours to decide. His startup needed 500 housings for beta units shipping to pilot customers next month.
The call came at 4 PM on a Friday. A Tier 1 automotive supplier’s injection molding resin vendor couldn’t deliver next week’s order. Force majeure.
A product manager at a medical device company got the call on a Tuesday morning. Their primary resin supplier declared force majeure. Production stopped.
A medical device startup spent eight months perfecting their prototypes. The design won awards. Investors lined up. Then they scaled to production, and the failure rate hit 40 percent.
When selecting the manufacturing process for functional prototypes or low-volume production, the decision can often feel overwhelming.
The production line was ready. Materials were in. Demand was real. Then a single tool cracked.
The first prototype looked perfect on screen. Clean geometry. Tight tolerances. Everyone nodded in the review.
In early 2020, a mid-sized molding supplier in Eastern Europe found itself in an unforeseen crisis.
In Silicon Valley, a product team racing against time had their prototype ready but something was wrong.
The part looked right on the screen. It cleared internal review. It even passed a quick Design For Manufacturing (DFM) check inside the Computer Aided Design environment.
Rapid Prototyping Is No Longer a Safety Net. It’s the Critical Path.
In the rapidly evolving healthcare and medical product development marketplace...
In the realm of modern manufacturing, CNC machining redefines precision...
The EV industry is evolving rapidly with the help of 3D printing...
Dramatic healthcare needs during COVID-19 created urgent manufacturing demand...
Getting quotes has never been more convenient...
Another successful year for PrintForm driven by customer satisfaction...
Our molding experience has grown tremendously over the years...
SLS technology is suitable for complex designs and applications...
Experience the power of PrintForm’s CNC machining services, where precision meets versatility. Our advanced manufacturing processes and skilled engineering team offer an extensive array of finish and secondary processing options. With a commitment to exceeding your expectations, we prioritize your unique requirements over any specific technology or machine. Whether it’s high-quality plastic or metal components, our CNC machining capabilities deliver unmatched dimensional accuracy, critical surface finishes, and material-specific properties. Trust PrintForm to provide precision engineering solutions that empower your success in today’s competitive landscape.
A strong and corrosion-resistant material commonly used for CNC machining parts like precision components, medical instruments, and automotive components.
A durable thermoplastic material suitable for CNC machining complex parts like gears, bearings, and bushings, known for its excellent dimensional stability and low friction properties.
A versatile engineering plastic widely used for CNC machining components such as precision gears, rollers, and valve bodies due to its low friction, high strength, and dimensional stability.
An impact-resistant and transparent material often CNC machined into parts like safety goggles, electronic enclosures, and automotive lighting covers due to its excellent strength and optical clarity.
A strong and flexible material used for CNC machining parts like gears, pulleys, and bearings due to its high wear resistance, low friction, and excellent mechanical properties.
A durable and impact-resistant thermoplastic commonly CNC machined into parts like prototypes, enclosures, and consumer goods due to its good mechanical properties, ease of machining, and wide range of available colors.
A metal alloy known for its excellent machinability and corrosion resistance, often CNC machined into parts like fittings, valves, and decorative components due to its aesthetic appeal and durability.
A highly conductive and malleable material often CNC machined into electrical connectors, heat sinks, and RF shields due to its excellent electrical and thermal properties.
A low-carbon steel commonly CNC machined into parts like brackets, shafts, and structural components due to its strength, machinability, and cost-effectiveness.
A lightweight and versatile material used for CNC machining applications like packaging inserts, architectural models, and signage due to its ease of machining, low density, and impact-absorbing properties.
A high-performance engineering plastic known for its excellent dimensional stability, low friction, and high wear resistance, often CNC machined into parts like bushings, gears, and bearings.
A strong and corrosion-resistant material commonly used for CNC machining parts like precision components, medical instruments, and automotive components.
A durable thermoplastic material suitable for CNC machining complex parts like gears, bearings, and bushings, known for its excellent dimensional stability and low friction properties.
A versatile engineering plastic widely used for CNC machining components such as precision gears, rollers, and valve bodies due to its low friction, high strength, and dimensional stability.
An impact-resistant and transparent material often CNC machined into parts like safety goggles, electronic enclosures, and automotive lighting covers due to its excellent strength and optical clarity.
A strong and flexible material used for CNC machining parts like gears, pulleys, and bearings due to its high wear resistance, low friction, and excellent mechanical properties.
A durable and impact-resistant thermoplastic commonly CNC machined into parts like prototypes, enclosures, and consumer goods due to its good mechanical properties, ease of machining, and wide range of available colors.
A metal alloy known for its excellent machinability and corrosion resistance, often CNC machined into parts like fittings, valves, and decorative components due to its aesthetic appeal and durability.
A highly conductive and malleable material often CNC machined into electrical connectors, heat sinks, and RF shields due to its excellent electrical and thermal properties.
A low-carbon steel commonly CNC machined into parts like brackets, shafts, and structural components due to its strength, machinability, and cost-effectiveness.
A lightweight and versatile material used for CNC machining applications like packaging inserts, architectural models, and signage due to its ease of machining, low density, and impact-absorbing properties.
A high-performance engineering plastic known for its excellent dimensional stability, low friction, and high wear resistance, often CNC machined into parts like bushings, gears, and bearings.
| Material | Mechanical Properties | Physical Properties | Chemical Properties | Features | Common Applications |
|---|---|---|---|---|---|
|
Tensile Strength: 60-70 MPa Impact Strength: 10-20 kJ/m² Heat Deflection Temperature: 135-150°C |
Transparent or translucent Good dimensional stability |
Resistant to many chemicals and oils
|
Excellent transparency High temperature resistance |
Aerospace and Defense: Transparent canopies, Medical: Medical device components |
|
|
Tensile Strength: 40-60 MPa Impact Strength: 5-20 kJ/m² Heat Deflection Temperature: 100-120°C |
Various colors available Good dimensional stability |
Resistant to many chemicals and oils
|
Suitable for high-temperature applications |
Aerospace and Defense: Engine components, Automotive: Engine components |
|
|
Tensile Strength: 60-80 MPa Impact Strength: 20-40 kJ/m² Density: 1.03 g/cm³ Melting Point: 220-260°C |
Various colors available Low density Good dimensional stability |
Resistant to many chemicals and oils
|
High strength and impact resistance Lightweight |
Automotive: Bumpers, Aerospace and Defense: Structural components |
|
|
Tensile Strength: 40-60 MPa Impact Strength: 5-20 kJ/m² Density: 1.03 g/cm³ Melting Point: 220-260°C |
Black color Low density Good dimensional stability |
Resistant to many chemicals and oils
|
Black appearance
Lightweight – Durable |
Consumer Products: Electronics casings, automotive interior parts |
|
|
Tensile Strength: 40-60 MPa Impact Strength: 5-20 kJ/m² Density: 1.03 g/cm³ Melting Point: 220-260°C |
White color Low density Good dimensional stability |
Resistant to many chemicals and oils
|
White appearance
Lightweight Durable |
Consumer Products: Electronics casings, toys, kitchen appliances |
|
|
ABS |
Good impact resistance |
Density: 1.03 g/cm³ |
Resistant to diluted acids, alkalis |
High strength, versatility,
cost-effective |
Automotive, Consumer Products |
|
ABS – M30i |
– Good tensile strength |
– Density: 1.04 g/cm³ |
– Medical grade |
– Biocompatible, sterilizable, suitable for medical devices |
Medical |
|
ABS ESD |
– Static-dissipative properties |
– Density: 1.06 g/cm³ |
– ESD protection |
– Prevents electrostatic discharge, suitable for electronics |
Aerospace and Defense, Consumer Products |
|
ABS-Like |
– High toughness and durability |
– Density: Varies by formulation |
– Resistant to various chemicals |
– Resembles ABS but may offer specific improvements |
Varies by formulation |
|
Accura 25 |
– High accuracy and resolution |
– Density: Varies by formulation |
– Photopolymer |
– Used in stereolithography 3D printing, fine details |
Consumer Products, Medical, Aerospace and Defense |
|
Accura 60 |
– High strength and durability |
– Density: Varies by formulation |
– Photopolymer |
– Tough and durable, suitable for functional prototypes |
Consumer Products, Aerospace and Defense |
|
Accura AMX Rigid Black |
– High impact resistance |
– Density: Varies by formulation |
– Photopolymer |
– Rigid and durable, good for functional prototypes |
Consumer Products, Aerospace and Defense |
|
Accura ClearVue |
– High transparency and clarity |
– Density: Varies by formulation |
– Photopolymer |
– Crystal clear appearance, ideal for clear parts |
Consumer Products, Medical |
|
Accura Xtreme Grey/White |
– High toughness and durability |
– Density: Varies by formulation |
– Photopolymer |
– Resistant to high temperatures, strong and rigid |
Consumer Products, Aerospace and Defense |
|
ASA |
– Excellent UV resistance |
– Density: 1.07 g/cm³ |
– Weather-resistant |
– Outdoor durability, retains color and strength in sunlight |
Automotive, Consumer Products |
|
Nylon |
– High tensile strength |
– Density: 1.15 g/cm³ |
– Resistant to moisture, chemicals |
– Tough and durable, suitable for functional parts |
Aerospace and Defense, Automotive, Consumer Products |
|
Nylon 11 Flame Retardant |
– Flame retardant properties |
– Density: Varies by formulation |
– Flame-resistant |
– Fire safety, suitable for applications requiring flame resistance |
Aerospace and Defense, Automotive |
|
Nylon 12 |
– Good chemical resistance |
– Density: 1.02 g/cm³ |
– Resistant to oils, greases |
– Versatile, suitable for various industrial applications |
Aerospace and Defense, Automotive, Consumer Products, Oil and Gas |
|
Nylon 6 |
– High impact strength |
– Density: 1.14 g/cm³ |
– Resistant to moisture, abrasion |
– Durable, excellent for applications requiring impact resistance |
Automotive, Consumer Products |
|
PA 12 Glass Beads |
– Improved stiffness and dimensional stability |
– Density: Varies by formulation |
– Reinforced with glass beads |
– Increased stiffness, suitable for engineering applications |
Automotive, Aerospace and Defense |
|
PC-ISO |
– High strength and heat resistance |
– Density: Varies by formulation |
– Biocompatible |
– Suitable for medical and aerospace applications |
Aerospace and Defense, Medical |
|
PC+ABS |
– Good impact resistance |
– Density: Varies by formulation |
– Resistant to chemicals |
– Blends properties of PC and ABS, versatile material |
Automotive, Consumer Products |
|
PETG |
– Excellent transparency and impact resistance |
– Density: 1.27 g/cm³ |
– Food-safe, BPA-free |
– Clarity and toughness, ideal for packaging and displays |
Consumer Products, Medical |
|
PLA |
– Biodegradable and easy to print |
– Density: 1.24 g/cm³ |
– Biodegradable |
– Eco-friendly, easy to 3D print |
Consumer Products, Medical |
|
Polycarbonate (PC) |
– High impact resistance, optical clarity |
– Density: 1.20 g/cm³ |
– Excellent optical properties |
– Exceptional clarity and strength, suitable for transparent parts |
Aerospace and Defense, Consumer Products, Medical |
|
Polypropylene |
– Low density and good chemical resistance |
– Density: 0.90 g/cm³ |
– Resistant to moisture, chemicals |
– Lightweight, suitable for low-stress applications |
Consumer Products, Automotive |
|
Rubber-Like |
– Flexible and rubber-like properties |
– Density: Varies by formulation |
– Flexible elastomer |
– Mimics rubber, suitable for gaskets and seals |
Automotive, Consumer Products |
|
Somos Evolve |
– High strength and heat resistance |
– Density: Varies by formulation |
– Photopolymer |
– Engineering-grade material, suitable for functional prototypes |
Aerospace and Defense, Automotive |
|
Somos PerFORM |
– High stiffness and heat resistance |
– Density: Varies by formulation |
– Photopolymer |
– Strong and stiff, ideal for high-temperature applications |
Aerospace and Defense |
|
Somos Waterclear |
– High transparency and clarity |
– Density: Varies by formulation |
– Photopolymer |
– Transparent, suitable for clear prototypes and parts |
Consumer Products, Medical |
|
Somos Watershed |
– Excellent clarity and water resistance |
– Density: Varies by formulation |
– Photopolymer |
– Waterproof, suitable for water-resistant parts |
Consumer Products, Medical |
|
ST-130 |
– High toughness and durability |
– Density: Varies by formulation |
– Photopolymer |
– Rigid, tough, and durable, good for functional prototypes |
Consumer Products, Aerospace and Defense |
|
TPU 88A |
– Flexible and elastomeric properties |
– Density: Varies by formulation |
– Thermoplastic polyurethane |
– Flexibility and resilience, suitable for elastomeric parts |
Automotive, Consumer Products, Medical |
|
Ultem 1010 |
– High strength, heat, and chemical resistance |
– Density: 1.27 g/cm³ |
– Flame-resistant, UL 94 V0 |
– Engineering-grade thermoplastic with excellent properties |
Aerospace and Defense, Automotive, Oil and Gas |
|
Ultem 9085 |
– High strength, heat, and chemical resistance |
– Density: 1.27 g/cm³ |
– Flame-resistant, UL 94 V0 |
– Suitable for aerospace and transportation applications |
Aerospace and Defense, Automotive |
|
Vero |
– Rigid and durable |
– Density: Varies by formulation |
– Photopolymer |
– Versatile material, good for prototypes and models |
Consumer Products, Aerospace and Defense |
|
VeroClear |
– High transparency and clarity |
– Density: Varies by formulation |
– Photopolymer |
– Transparent appearance, ideal for clear parts |
Consumer Products, Medical |
PrintForm, LLC
3423 Piedmont Rd NE, Atlanta, GA 30305, USA
:(404) 999-4916
:(404) 937-6257
: info@printform.com
