PA66 vs PA6G
Polymer · grade comparison
PA66 and PA6G are both polymer grades, both engineering plastic. Both yield at about 80 MPa — strength does not separate them. PA66 is the more ductile: elongation 40% versus 25% for PA6G. PA6G is stiffer (3.4 GPa vs 3 GPa) and PA6G conducts heat better (0.29 W/m·K vs 0.25 W/m·K). On the shop floor, PA6G machines more easily (very good vs good) and PA66 welds better (very good vs poor).
PA66Choose it when the part is bent, formed or impact-loaded, or when it will be welded.
PA6GChoose it when the part is machined in volume.
PA66 vs PA6G: 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
Yield Strength (0.2% offset)
Elongation at Break
Compressive Strength
Compressive Modulus
Flexural Strength
Flexural Modulus
Fracture Toughness (K_IC)
Izod Impact, Notched
Hardness, Shore D
Hardness, Rockwell M
Hardness, Rockwell R
Same in both: Poisson's Ratio 0.39 · Tensile Strength (Ultimate) 82 MPa11.9 ksi · Shear Strength 60 MPa8.7 ksi
Physical
Density and transition temperatures.
Density
Melting Temperature (Tm)
Glass Transition (Tg)
Water Absorption (Saturation)
Refractive Index
Same in both: Water Absorption (24 h) 1.3%
Thermal
How each material carries heat and how hot it can run.
Thermal Conductivity
Specific Heat Capacity
Max Service Temperature (continuous)
Heat Deflection Temp. @ 0.45 MPa
Heat Deflection Temp. @ 1.8 MPa
Vicat Softening Point (B50)
Max Service Temperature (short-term)
Same in both: Thermal Expansion (CTE, 20–100 °C) 85 µm/m·K47.2 µin/in·°F · Min Service Temperature -40°C-40 °F · Limiting Oxygen Index 25%
Electrical
Conductivity and insulation.
Dielectric Strength
Dielectric Constant (1 MHz)
Dissipation Factor (1 MHz)
Same in both: Electrical Resistivity 1×10¹² Ω·m3.94×10¹⁹ µΩ·in · 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
Formability (cold)
Polishability
Mold Shrinkage
Melt Flow Rate
Processing Melt Temperature (typ.)
Mold Temperature (typ.)
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 | PA66 | PA6G |
|---|---|---|
| Default condition | Unfilled | Cast Unfilled |
| Relative cost | $$ Standard | $$ Standard |
| Min. machined wall | 0.5 mm | 0.5 mm |
| Best machined surface | Ra 0.8 µm | Ra 0.8 µm |
Both are offered for CNC machining, Sheet metal and Injection molding. Both take the same 6 finishes: Chrome Plating (Plastic), EMI Shielding Coating, Painting, Soft Touch Coating, Spray Painting, UV Coating.
PA66 vs PA6G — frequently asked
What is the difference between PA66 and PA6G?
PA66 and PA6G are both polymer grades, both engineering plastic. Both yield at about 80 MPa — strength does not separate them. PA66 is the more ductile: elongation 40% versus 25% for PA6G.
Which is cheaper, PA66 or PA6G?
Both sit in the same relative cost tier ($$, standard); the part price will be decided by machining time, tolerance and quantity rather than by the material.
Which is easier to machine, PA66 or PA6G?
PA6G. Its machinability rates very good (80/100) against good (65/100) for PA66; for welding the order is PA66 first (very good, 70/100) then PA6G (poor, 30/100).
Ready to make it?
Upload a CAD file and FabDigit prices the part in PA66 and PA6G 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.