PA6 vs PA6/66
Polymer · grade comparison
PA6 and PA6/66 are both polymer grades. PA6 is the stronger of the two: tensile strength 80 MPa (11.6 ksi) against 76 MPa (11 ksi) for PA6/66, about 5% more. PA6 is stiffer (3 GPa vs 2.8 GPa). On the shop floor, PA6/66 welds better (very good vs good) and PA6 sits in a lower cost tier (budget, $) than PA6/66 (standard, $$).
PA6Choose it when strength drives the design, or when cost is the deciding factor.
PA6/66Choose it when it will be welded.
PA6 vs PA6/66: propertiesHow to read these bars
- One bar per material. A full bar is the highest value among all polymer grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
How to read these bars
- One bar per material. A full bar is the highest value among all polymer grades in the FabDigit library; each bar is drawn as a share of that.
- The better value (by the usual engineering direction) is in bold. Rows with no direction — density, thermal conductivity — have no bold.
- Values are typical room-temperature figures for the condition named on each card.
- Confirm against the certified mill or resin datasheet before design release.
Mechanical
Strength, stiffness, ductility and hardness at room temperature.
Elastic (Young's) Modulus
Shear Modulus
Bulk Modulus
Tensile Strength (Ultimate)
Yield Strength (0.2% offset)
Compressive Strength
Compressive Modulus
Flexural Strength
Flexural Modulus
Shear Strength
Fracture Toughness (K_IC)
Hardness, Shore D
Hardness, Rockwell M
Hardness, Rockwell R
Same in both: Poisson's Ratio 0.39 · Elongation at Break 60% · Izod Impact, Notched 55 J/m1 ft·lbf/in
Physical
Density and transition temperatures.
Density
Melting Temperature (Tm)
Glass Transition (Tg)
Water Absorption (24 h)
Water Absorption (Saturation)
Refractive Index
Thermal
How each material carries heat and how hot it can run.
Min Service Temperature
Heat Deflection Temp. @ 0.45 MPa
Heat Deflection Temp. @ 1.8 MPa
Vicat Softening Point (B50)
Same in both: Thermal Conductivity 0.25 W/m·K0.14 BTU/hr·ft·°F · Specific Heat Capacity 1,700 J/kg·K0.41 BTU/lb·°F · Thermal Expansion (CTE, 20–100 °C) 90 µm/m·K50 µin/in·°F · Max Service Temperature (continuous) 90°C194 °F · Limiting Oxygen Index 24% · Max Service Temperature (short-term) 150°C302 °F
Electrical
Conductivity and insulation.
Dielectric Constant (1 MHz)
Dissipation Factor (1 MHz)
Same in both: Electrical Resistivity 1×10¹² Ω·m3.94×10¹⁹ µΩ·in · Dielectric Strength 25 kV/mm635 V/mil · Volume Resistivity 1×10¹⁴ Ω·cm · Surface Resistivity 1×10¹³ Ω · Comparative Tracking Index (CTI) 600 V
Chemical & Environmental
Corrosion and environmental resistance (0–100 scores).
Corrosion Resistance
Same in both: UV / Weathering Resistance 30 / 100
Manufacturability
FabDigit workshop ratings (0–100 scores) — how each material behaves on the machine.
Machinability
Weldability
Mold Shrinkage
Melt Flow Rate
Mold Temperature (typ.)
Same in both: Formability (cold) 60 / 100 · Polishability 55 / 100 · Processing Melt Temperature (typ.) 260°C500 °F
Sustainability
Primary-production footprint per kilogram.
Embodied Energy (primary production)
Embodied Carbon (primary production)
Embodied Water
Typical Recycled Content
Common Calculations
Ratios derived from the values above.
Specific Strength (UTS / density)
Specific Stiffness (E / density)
Modulus of Resilience
Same in both: Thermal Diffusivity 0.1 mm²/s · Thermal Shock Resistance Index 0
Strength versus weight
Yield strength against density for every polymer grade in the FabDigit library; the compared grades are highlighted. Up and left is stronger for its weight.
Manufacturing and finishing
| Capability | PA6 | PA6/66 |
|---|---|---|
| CNC machining | Yes | — |
| Sheet metal | Yes | — |
| Injection molding | Yes | — |
| Default condition | Unfilled | — |
| Relative cost | $ Budget | $$ Standard |
| Min. machined wall | 0.5 mm | — |
| Best machined surface | Ra 0.8 µm | — |
| Chrome Plating (Plastic) | Yes | — |
| EMI Shielding Coating | Yes | — |
| Painting | Yes | — |
| Soft Touch Coating | Yes | — |
| Spray Painting | Yes | — |
| UV Coating | Yes | — |
PA6 vs PA6/66 — frequently asked
Is PA6 stronger than PA6/66?
Yes. PA6 has a typical tensile strength of 80 MPa (11.6 ksi) against 76 MPa (11 ksi) for PA6/66 — about 5% more.
Which is cheaper, PA6 or PA6/66?
PA6 is the lower-cost material: it sits in the budget tier ($) while PA6/66 is standard ($$). Part price depends far more on geometry, tolerance and quantity than on raw stock — upload a CAD file for a live quote.
Which is easier to machine, PA6 or PA6/66?
PA6, by a small margin. Both rate good for machinability — 68/100 against 62/100 for PA6/66; for welding the order is PA6/66 first (very good, 78/100) then PA6 (good, 62/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in PA6 and PA6/66 side by side — material, machining time, tolerance and finish in one quote. Certified material data ships with the order on request.
Typical handbook values for the conditions named above, normalised for comparison. Hardness on non-Brinell scales is converted approximately for charting only. Request certified data with your order for design-critical properties.