GRAM M1 Iron Cast weights are cast in iron with a rectangular profile, covering a range from 1 kg to 200 kg for the calibration and verification of balances. They deliver dependable OIML M1 class accuracy, with a maximum permissible error of just ±50 mg at a nominal value of 1 kg — the right choice for traceability of M2 and lower-class weights, and for verifying weighing instruments of OIML accuracy class II. Built to handle the demands of heavy-duty calibration, each weight withstands daily use in industrial, laboratory and calibration environments. Optional M Class traceability certificates, covering the full range up to 200 kg, add documented proof of accuracy.