The coefficient of thermal expansion (CTE) of a material is a critical material characteristicwhen working in machine design. This measures the fractional change in size per degree change in temperature at a constant pressure. Materials with lower CTE indicate a lower change in size through a temperature gradient while materials with higher CTE exhibit the opposite reaction.
At Carter Bearings, we specialize in extreme environment applications which regularly operate at high or cryogenic temperatures. Ensuring the bearing continues to have optimal performance at the operating temperature relies heavily on the stack-up of CTE within the system. If not carefully designed, dissimilar materials expanding or contracting can potentially eliminate the internal clearance and seize the bearings.
Below you will find the most common material we use on a regular basis for bearing design. Please reach out to our engineers to learn more about how we can optimize your bearing design.
| Material |
Coefficient of Thermal Expansion [µm/m/°C ] & [10-6/K] |
Coefficient of Thermal Expansion (µin/in/°F) |
| 52100 Chrome Steel |
11.9 |
6.6 |
| 440C Stainless Steel |
12.5 |
6.9 |
| 316 Stainless Steel |
16 |
8.9 |
| 304 Stainless Steel |
17.3 |
9.6 |
| BG42 |
9.81 |
5.5 |
| Stellite 6B |
14.1 |
7.8 |
| Cronidur 30 |
9.9 |
5.5 |
| XD15NW |
10.4 |
5.8 |
| Zirconia |
10 |
5.6 |
| Silicon Nitride |
2.8 |
1.6 |
| Silicon Carbide |
3.9 |
2.2 |
| Alumnia |
8.2 |
4.5 |
| PEEK |
55 |
30.6 |
| PCTFE |
70 |
38.9 |