Convert Microinches per inch per degree Fahrenheit to ppm per kelvin
Convert Microinches per inch per degree Fahrenheit (μin/(in·°F)) to ppm per kelvin (ppm/K) instantly and accurately.
Conversion Formula
ppm/K = μin/(in·°F) × 1.8
About Microinches per inch per degree Fahrenheit
The microinch per inch per degree Fahrenheit (μin/(in·°F)) equals exactly 9/5 × 10⁻⁶ /K = 1 ppm/°F. It is the native US CTE unit in ASTM E228 and ASTM E831 standards; most US material datasheets list CTE values in this unit. Steel: ≈6.7 μin/(in·°F); aluminium: ≈12.8 μin/(in·°F); titanium: ≈4.9 μin/(in·°F). 1 μin/(in·°F) = 1 ppm/°F.
About ppm per kelvin
The ppm/K (= μm/(m·K) exactly) equals 10⁻⁶ /K and is the universal CTE unit in international materials standards (ISO, EN, DIN). Aluminium: 23.1 ppm/K; steel: ≈12 ppm/K; ordinary glass: ≈9 ppm/K; fused silica: 0.55 ppm/K; Invar: ≈1.2 ppm/K. 1 ppm/K = 10⁻⁶ /K.
Quick Reference Table
| Microinches per inch per degree Fahrenheit (μin/(in·°F)) | ppm per kelvin (ppm/K) |
|---|---|
| 1 μin/(in·°F) | 1.8 ppm/K |
| 2 μin/(in·°F) | 3.6 ppm/K |
| 5 μin/(in·°F) | 9 ppm/K |
| 10 μin/(in·°F) | 18 ppm/K |
| 25 μin/(in·°F) | 45 ppm/K |
| 50 μin/(in·°F) | 90 ppm/K |
| 100 μin/(in·°F) | 180 ppm/K |