Made of Troemner Alloy 8, a specially developed austenitic stainless steel that possesses closely controlled density, extremely low magnetic permeability, good stability, and resistance to corrosion and handling damage
Exclusive material has a density of 8.0 at 25°C (controlled to ±0.1%), is essentially nonmagnetic in the annealed condition, and will not transform to magnetic under any combination of temperature and cold work down to -195.5°C (-320°F) Fractional weights 500mg to 50mg are made of stainless steel (30mg weights are aluminum); fractional weights 3mg and below are aluminum The UltraClass weight tolerance is equal to ANSI/ASTM E617 Class 0 and exceeds OIML R 111 Class E2 This class is used as a reference standard for calibrating other reference standards and weights and is appropriate for calibrating high-precision analytical balances with a readability as low as 0.01mg Weights are supplied with a NIST/NVLAP Weight Calibration Certificate Weights supplied in a rugged, precision-fit, high quality polycarbonate case