Basics
Cast nylon technical properties
Use this table for design or material comparison. The values are general PA6G values and vary with grade, moisture and test conditions.
Mechanical values
| Property | Typical value |
|---|---|
| Density | 1.14 to 1.15 g/cm³ |
| Tensile strength | About 80 to 82 MPa |
| Elastic modulus | About 3200 to 3400 MPa |
| Elongation at break | 30 to 55 % |
| Hardness | About 80 to 85 Shore D |
| Coefficient of friction | About 0.26 to 0.42 (depends on test) |
Thermal values
| Property | Typical value |
|---|---|
| Melting temperature | 217 to 220 °C |
| Continuous use | Up to +100 °C |
| Short-term use | Up to 170 to 180 °C |
| Lower service temperature | About -30 °C |
| Thermal expansion | About 7 to 8.5 × 10⁻⁵ / °C |
See temperature limits for more.
Moisture and electrical values
| Property | Typical value |
|---|---|
| Water absorption, 24 h in water | About 1.2 % |
| Water absorption, saturated | About 5.5 to 7 % |
| Volume resistivity | About 10¹⁴ Ω·cm |
| Flammability (UL94) | HB |
How to read these values
- Dry and wet values differ. Moist cast nylon is tougher but softer.
- A table value is not a part value. Working temperature and load type decide real behaviour.
- Makers use different standards. ASTM and ISO values do not compare one to one.
For weight use the weight guide or the calculator.
Compared with metals
| Property | Cast nylon | Aluminium | Steel |
|---|---|---|---|
| Density (g/cm³) | 1.15 | 2.7 | 7.85 |
| Elastic modulus (MPa) | About 3300 | About 70,000 | About 210,000 |
| Thermal expansion (× 10⁻⁵ / °C) | About 8 | About 2.3 | About 1.2 |
Three design lessons
Cast nylon bends much more
Steel's modulus is about 60 times that of cast nylon. With the same section and load, a cast nylon part deflects about 60 times more. Shorten support spacing on long plates or increase thickness.
A thicker section works best
In bending, thickness counts to the third power. Doubling the thickness cuts deflection to about one eighth under the same load. Cast nylon is light, so a thick design is rarely a problem.
Long-term load needs its own check
Plastics can deform over time under constant load. This is called creep, and heat makes it worse. Do not use the tensile value as a long-term load limit.
A practical order of checks
- Check temperature and chemical suitability.
- Calculate deflection under load.
- Add allowance for moisture and thermal expansion.
- Run a trial part in real conditions.
Frequently asked questions
What is the density of cast nylon?
About 1.15 g/cm³. That is enough for weight calculations.
How hard is cast nylon?
Typically 80 to 85 Shore D. It drops a little as the material absorbs moisture.
Do these values apply to your product?
The table shows general PA6G values. If you need exact values for your job, write to us.
Figures are typical values published by manufacturers and vary with grade and test conditions. Ask us for exact values.