PA6
also Akulon, Capron
PA6 (polycaprolactam) is a semi-crystalline aliphatic polyamide made by ring-opening polymerisation of caprolactam, combining high strength and toughness with good wear and oil resistance; dry unfilled stock runs 80 MPa tensile strength, 60% elongation, 3 GPa modulus and service to 90 °C.
PA6 grades and fills
PA6 is supplied in 19 conditions, soft to hard.
- Impact Modified
- MoS2 Cond
- PTFE/Oil Lubricated
- ESD/Conductive
- Heat Stabilized
- Extruded
- MoS2 Filled
- FR V-0
- MoS2 Dry
- Cast (PA6 G)
- Mineral Filled
- Forward AM Ultrasint PA6 MF
- GF15
- GF20
- GF30
- GF40
- CF20
- GF50
- CF30
Compare all 19 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
rubber-toughened / super-tough PA6 | Select for snap-fits, cold-impact parts and thin living hinges where notched toughness at low temperature is the driver. | 45 | 50 | 150 | 105 HRR |
MoS2 Filled | Molybdenum-disulfide-filled PA6 at 50% RH moisture equilibrium: water plasticization roughly halves stiffness and strength while sharply raising ductility and notched impact. | 52 | 58 | 100 | 76 Shore D |
PTFE / oil-filled lubricated bearing grade | Pick for lowest coefficient of friction and highest allowable sliding speed in unlubricated bearings, at the cost of some strength. | 62 | 65 | 25 | 80 Shore D |
ESD / conductive compound (carbon black or CF/CNT) | For electronics handling trays, fuel-system parts and explosion-risk areas needing controlled surface resistivity. | 68 | 70 | 15 | 82 Shore D |
long-term thermal aging resistant | Use for under-hood, motor and appliance parts held above ~100 °C for thousands of hours; copper/organic stabilizers slow oxidative embrittlement. | 75 | 80 | 50 | 81 Shore D |
PA6 rod/plate/tube (semi-finished) | Pick when the part is machined from stock: extruded PA6 rod/plate offers uniform crystallinity and good machining behaviour. | 78 | 80 | 40 | 82 Shore D |
Molybdenum disulfide lubricated bearing grade | Use for dry-running bushings, wear strips and gears: MoS2 nucleates finer crystals, giving higher stiffness, better wear and lower creep than natural PA6. | 80 | 20 | 88 HRM | |
Flame retardant, UL 94 V-0 rated | Required for electrical enclosures, connectors and breaker parts needing V-0 at 0.75–1.6 mm; halogen-free (red P / N-P) or brominated versions available. | 80 | 8 | ||
MoS2 Filled | Molybdenum-disulfide-nucleated PA6 tested dry-as-molded: highest stiffness and strength, lower toughness than the moisture-conditioned state. | 82 | 84 | 25 | 82 Shore D |
Cast nylon 6 | Use for large-diameter rods, thick plate, big gears and wear pads — higher crystallinity gives more stiffness, creep resistance and better wear than extruded PA6. | 82 | 25 | 88 HRM | |
low-warp, paintable | Use where isotropic shrinkage, flat surfaces and Class-A paintability matter more than peak strength (covers, trim, mirror housings). | 88 | 90 | 5 | 85 Shore D |
SLS powder | 91 | 2.1 | |||
15% short glass fiber reinforced | Light reinforcement when moderate stiffness gain is wanted with good surface finish and low warpage. | 115 | 6 | ||
20% short glass fiber reinforced | Balanced stiffness/toughness reinforcement for housings, brackets and covers. | 140 | 4.5 | ||
30% short glass fiber reinforced | The workhorse structural PA6 grade: best strength/stiffness per cost for gears, pump bodies, power-tool housings and metal-replacement brackets. | 180 | 3.5 | 95 HRM | |
40% short glass fiber reinforced | High-stiffness structural grade for load-bearing parts and metal replacement where warpage and anisotropy are acceptable. | 205 | 3 | ||
20% short carbon fiber reinforced | Choose for lightweight stiff parts with static-dissipative behaviour and lower warpage/wear than glass at the same modulus. | 210 | 2.2 | ||
50% short glass fiber reinforced | Maximum-stiffness PA6 compound for highly loaded, dimensionally demanding parts; abrasive to tooling and prone to fiber-rich surfaces. | 230 | 2.5 | ||
30% short carbon fiber reinforced | Highest specific stiffness PA6 compound; conductive/ESD-safe and low wear, but costly and highly anisotropic. | 255 | 1.8 |
Supply forms, finishes and certifications
Ways PA6 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
Food/FDA | Food-contact / FDA-compliant natural grade | Certification |
UV Stabilized | UV stabilized / weather resistant | Grade option |
UnfilledDefault | Natural/uncompounded PA6 | Standard supply |
What is PA6?
PA6 (polycaprolactam) is a semi-crystalline aliphatic polyamide made by ring-opening polymerisation of caprolactam, combining high strength and toughness with good wear and oil resistance; dry unfilled stock runs 80 MPa tensile strength, 60% elongation, 3 GPa modulus and service to 90 °C. It is the standard resin for moulded gears, bearings, clips and power-tool housings, glass-filled structural parts, extruded stock and cast PA6 G. Its melting point (about 220 °C) is below PA66, but toughness and surface finish are better. Moisture uptake is high (8–9% at saturation), so parts grow and lose stiffness and strength — design to both dry and conditioned data; mineral acids, phenols, UV and long-term heat all need attention. PA6 has a density of 1.14 g/cm³ (0.0412 lb/in³), lighter than 60% of polymer grades. Its glass-transition temperature is 58°C (136 °F). PA6 has a yield strength of 75 MPa (10.9 ksi) and a tensile strength of 80 MPa (11.6 ksi) — stronger than 84% of polymer grades. Elongation at break is 60% and the elastic modulus is 3 GPa (0.435 Msi).
What is PA6 used for?
- Automotive gears
- Pulleys
- Caster wheels
Advantages
- High strength — 75 MPa (10.9 ksi), better than 84% of polymer grades
- Tough — resists crack growth — 3.5 MPa·√m (3.19 ksi·√in), better than 81% of polymer grades
Limitations
- Absorbs moisture — dry before molding — 1.7%, worse than 94% of polymer grades
- High embodied carbon — 7.6 kg CO₂/kg, worse than 81% of polymer grades
- Needs corrosion protection — 70/100, worse than 78% of polymer grades
PA6 properties
Typical room-temperature values in the Unfilled condition; bars are the position among polymer grades.
Physical6
PA6 has a density of 1.14 g/cm³ (0.0412 lb/in³), lighter than 60% of polymer grades. Its glass-transition temperature is 58°C (136 °F).
Mechanical17
PA6 has a yield strength of 75 MPa (10.9 ksi) and a tensile strength of 80 MPa (11.6 ksi) — stronger than 84% of polymer grades. Elongation at break is 60% and the elastic modulus is 3 GPa (0.435 Msi).
Thermal11
PA6 is rated for continuous service to 90°C (194 °F). It conducts heat at 0.25 W/m·K (0.144 BTU/hr·ft·°F), better than 72% of polymer grades. Thermal expansion is 90 µm/m·K (50 µin/in·°F).
Electrical7
PA6 is an electrical insulator with a dielectric strength of 25 kV/mm (635 V/mil) and a resistivity of 1×10¹² Ω·m.
Chemical & Environmental3
Corrosion resistance is very good (70/100), worse than 78% of polymer grades. UV resistance is poor.
Sustainability4
Producing a kilogram of PA6 takes about 125 MJ of energy and emits 7.6 kg of CO₂ — more than 75% of polymer grades. Typical recycled content is 5%.
Manufacturability8
PA6's machinability is good (68/100, better than 71% of polymer grades); weldability good (62/100); formability good (60/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the polymer family
Yield strength against density for every polymer grade FabDigit runs. PA6 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with PA6
Is PA6 easy to machine?
Machines easily with sharp positive-rake tools, high speed and low feed; stress-relieve thick stock and expect elastic spring-back plus dimensional drift as the part picks up moisture (glass/CF grades are abrasive—use carbide or PCD).
Can PA6 be welded?
Readily joined by ultrasonic, hot-plate, spin, vibration and hot-gas welding; adhesive bonding needs plasma/primer pretreatment, and the resin must be dry (<0.15% moisture) before any heat joining.
Can PA6 be formed, bent or molded?
Dry pellets to <0.10% water, mold at 250–280 °C melt / 60–100 °C tool with fast injection; account for 0.8–1.8% shrinkage (0.2–0.6% in GF grades) and post-condition in water or humid air for final dimensions.
Manufacturability
The process limits FabDigit's quote engine applies to PA6. Design inside these and the part quotes instantly; outside them it routes to an engineer.
CNC machining
| Machinability | Better68 / 100 |
|---|---|
| ISO material group | N.8 |
| Cutting speed (rough / finish) | 400 / 500 m/min |
| Minimum wall | 0.5 mm |
| Minimum internal radius | 1 mm |
| Drill depth limit | 10× diameter |
| Best surface (machined / polished) | Ra 0.8 / — |
| Hardenable after machining | No |
Sheet metal
| Formability | Fair60 / 100 |
|---|---|
| Weldability | Good62 / 100 |
Injection molding
| Mold shrinkage | 1.5 – 2.2 % |
|---|---|
| Wall thickness | 1 – 3.5 mm |
| Recommended draft | 1.5 ° |
| Pre-drying | 80 °C for 4 h |
| UV resistance | Fair |
PA6 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| heat/light stabilizer + lubricant packagtypical additive load in commercial grades | 0.1 – 1.5 | 0.5 |
| glass fiber0 in default; 15–50 wt% in GF variants | 0 – 50 | 0 |
| carbon fiberCF20/CF30 variants | 0 – 30 | 0 |
| MoS2bearing (Nylatron-type) variants | 0 – 2 | 0 |
| residual caprolactam monomer/oligomerextractables in as-polymerized resin | 0 – 1 | 0.5 |
| polycaprolactam (PA6 from ε-caprolactam)base resin; unfilled default grade | balance |
What surface finishes work on PA6?
Takes dyeing, printing and paint well after flame/plasma or primer treatment; can be electroplated with etch pretreatment, and MoS2/graphite grades polish to a low-friction bearing surface.
Surface treatments FabDigit runs on polymer parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Injection Molding Coating
Organic Coating
Metallization / Functional
Equivalent designations
Standards and trade names that resolve to PA6 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Trade names
- AkulonCapronDurethanNylatronUltramid BMarkForged OnyxOnyxOnyx FR
- Also called
- NylonNylon 6nylon CFNylon-CFPolyamide
How much does PA6 cost?
PA6 is a budget-cost polymer ($), cheaper than about 82% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
PA6 — frequently asked
What is PA6 used for?
PA6 is typically used for automotive gears, pulleys and caster wheels. In short: stiff; wear-resistant.
What is the yield strength of PA6?
PA6 has a typical yield strength of 75 MPa (10.9 ksi) and a tensile strength of 80 MPa (11.6 ksi) — stronger than 84% of polymer grades. Strength varies by condition: see the 19 listed tempers.
Is PA6 easy to machine?
Reasonably — machinability is rated good (68/100, better than 71% of polymer grades). Machines easily with sharp positive-rake tools, high speed and low feed; stress-relieve thick stock and expect elastic spring-back plus dimensional drift as the part picks up moisture (glass/CF grades are abrasive—use carbide or PCD).
Can PA6 be welded?
Yes — weldability is rated good (62/100). Readily joined by ultrasonic, hot-plate, spin, vibration and hot-gas welding; adhesive bonding needs plasma/primer pretreatment, and the resin must be dry (<0.15% moisture) before any heat joining.
What surface finishes work on PA6?
Takes dyeing, printing and paint well after flame/plasma or primer treatment; can be electroplated with etch pretreatment, and MoS2/graphite grades polish to a low-friction bearing surface.
Can PA6 be formed, bent or molded?
Dry pellets to <0.10% water, mold at 250–280 °C melt / 60–100 °C tool with fast injection; account for 0.8–1.8% shrinkage (0.2–0.6% in GF grades) and post-condition in water or humid air for final dimensions.
What is the maximum service temperature of PA6?
PA6 is rated for continuous use to about 90°C (194 °F), and briefly to 150°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does PA6 cost?
PA6 is a budget-cost polymer ($), cheaper than about 82% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Can FabDigit make parts in PA6?
Yes — PA6 is available for CNC machining, sheet metal and injection molding with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ISO 1874-1/-2 Plastics — Polyamide (PA) moulding and extrusion materials — ISO (2010)
- ASTM D4066 Standard Classification System for Nylon Injection and Extrusion Materials — ASTM (2019)
- Ultramid B (PA6) product range data — BASF (2023)
- Tecamid 6 / Tecamid 6 GF30 stock shape datasheets — Ensinger (2023)
- Forward AM Ultrasint PA6 MF — Technical Data Sheet — Forward AM
- Ertalon 6 SA, Nylatron GS/NSM datasheets — Mitsubishi Chemical Advanced Materials (2022)
- CAMPUS plastics datasheet collection (PA6, PA6-GF15…GF50) — CWFG / CAMPUS (2024)
- ASM Engineered Materials Handbook Vol. 2: Engineering Plastics — ASM International (1988)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.