Convert ppm per degree Fahrenheit to Millimetres per metre per kelvin
Convert ppm per degree Fahrenheit (ppm/°F) to Millimetres per metre per kelvin (mm/(m·K)) instantly and accurately.
Conversion Formula
mm/(m·K) = ppm/°F × 0.0018
About ppm per degree Fahrenheit
The ppm/°F (= μin/(in·°F) exactly) equals 9/5 × 10⁻⁶ /K ≈1.8 × 10⁻⁶ /K and is the dominant CTE unit in US ASTM standards, ASME piping codes, and mechanical engineering handbooks. Steel ≈6.7 ppm/°F; aluminium ≈12.8 ppm/°F; copper ≈9.4 ppm/°F. 1 ppm/°F = 9/5 × 10⁻⁶ /K.
About Millimetres per metre per kelvin
The mm/(m·K) equals exactly 10⁻³ /K = 1000 ppm/K and is used in structural and civil engineering for bridge girder and pipeline thermal-expansion calculations. Steel at 0.012 mm/(m·K) expands 12 mm per 100 m track per 10 K rise. Polymers: 0.07-0.20 mm/(m·K). 1 mm/(m·K) = 10⁻³ /K = 1000 ppm/K.
Quick Reference Table
| ppm per degree Fahrenheit (ppm/°F) | Millimetres per metre per kelvin (mm/(m·K)) |
|---|---|
| 1 ppm/°F | 0.0018 mm/(m·K) |
| 2 ppm/°F | 0.0036 mm/(m·K) |
| 5 ppm/°F | 0.009 mm/(m·K) |
| 10 ppm/°F | 0.018 mm/(m·K) |
| 25 ppm/°F | 0.045 mm/(m·K) |
| 50 ppm/°F | 0.09 mm/(m·K) |
| 100 ppm/°F | 0.18 mm/(m·K) |