Appendix D Unit conversions Quantity SI to English English to SI Length 1m=39.4in. 1in.=0.0254m 1cm=0.394in 1in.-2.54cm 1mm=0.0394in 1in.=25.4mm Force 1N=0.2251b 11b=4.445N Stress 1 MPa 145 psi 1 psi =6.895 kPa Work 1J-1N-m-8.86in.-b 1in.-lb=0.113J Surface energy 1J/m2-5.71×10-3in.b/in.2 1in.-b/in.2-175J/m2 Temperature ℉=1.8℃+32 ℃=0.56℉-17.8 Coefficient of thermal expansion cd1/℉]=0.55c1/C1 cd1/C]-1.8a1/℉] ©2003 by CRC Press LLCAppendix D Unit Conversions Quantity SI to English English to SI Length 1 m = 39.4 in. 1 cm = 0.394 in. 1 mm = 0.0394 in. 1 in. = 0.0254 m 1 in. = 2.54 cm 1 in. = 25.4 mm Force Stress Work Surface energy Temperature Coefficient of thermal expansion 1 N = 0.225 lb 1 MPa = 145 psi 1 J = 1 N·m = 8.86 in.-lb 1 J/m2 = 5.71 × 10–3 in. lb/in.2 °F = 1.8°C + 32 α[1/°F] = 0.55α[1/°C] 1 lb = 4.445 N 1 psi = 6.895 kPa 1 in.-lb = 0.113 J 1 in.-lb/in.2 = 175 J/m2 °C = 0.56°F – 17.8 α[1/°C] = 1.8α[1/°F] TX001_AppD_Frame Page 235 Saturday, September 21, 2002 5:15 AM © 2003 by CRC Press LLC