J390_198206 DUAL DIMENSIONING

This document covers a dual dimensioning practice that provides both U.S. customary inch-pound units and SI metric units for all dimensions on the field of the drawing. The scope does not include the “chart method”—whereby drawings are dimensioned only in SI units—with conversions to inch-pound units provided in chart form (usually computer-generated) on the drawing. Further information on the chart method is found in SAE Handbook Supplement J1066, “Recommended Guidelines for Company Metrication Programs in the Metalworking Industry.”