Precision laboratory test weights are used to calibrate Class I and II balances, and ASTM Class 4, 5 and 6 weights. ASTM Class 0 test weights are not individually marked with their weight value or individually serialized per ASTM E 617-13. Single-piece cylindrical test weights are Type I, ASTM Class 0 and OIML Class E1 and E2, and F1 and F2 with a one-piece construction.
These weights have no added adjusting material. Type II designs are cylindrical weights with adjusting cavities.