上海交通大学：《Design and Manufacturing》课程教学资源（讲义）Lecture 1 introduction to engineering design_conversion factors in mechanical design

Appendices A-39 APPENDIX 18 CONVERSION FACTORS TABLE A18-1 Conversion of U.S.Customary units to SI units:basic quantities U.S. Customary Quantity unit SI unit Symbol Equivalent units Length I foot (ft) 0.3048 meter m Mass I slug 14.59 kilogram kg Time I second 1.0 second s Force I pound (Ib)= 4.448 newton kg-m/s2 Pressure 1 Ib/in2 6895 pascal Pa N/m2 or kg/m-s? Energy 1 ft-Ib = 1.356 joule N-m or kg m'/s? Power 1 ft-lb/s = 1.356 watt W J/s TABLE A18-2 Other convenient conversion factors Length Stress.pressure.or unit loading I ft 0.3048 m 1 lb/in- 6.895 kPa 1 in 25.4 mm 1 Ib/ft? 0.0479 kPa 1 mi =5280 ft I kip/in2 6.895 MPa 1mi 1.609 km Section modulus 1km =1000 m 1in' 1.639×10mm3 1cm =10 mm 1m =1000 mm Moment of inertia 1 in = 4.162×103mm Area 1f2 0.0929 m2 Density 1in2 = 645.2 mm° 1slug/f3=515.4 kg/m 1m2 10.76 f2 Specific weight 1m2 = 10° mm2 1lb/h=157.1 N/m Volume Energy 1f3 =7.48 1 ft-lb 1.356 J gal 1 Btu =1.055 I fe =1728 J 1f3 0.0283 m3 IWh =3.600 J 1 gal = 0.00379 3 Torque or moment 1 gal = 3.785 L 1 Ib-in 0.1130 N.m 1m3 =1000 Power Volume flow rate Ihp =550 ft-Ib/s 1 fts 449 gal/min Ihp =745.7 W 1 ft'ls 0.0283 m'/s 1ftlb/s=1.356 W 1 gal/min 6.309×105m3s 1Btu/h=0.293 W I gal/min 3.785 L/min Temperature 1 L/min 16.67×106m3/5 TC) =[T℉)-32]5/9 TF) =TC】+32