Diamond Grinding Wheel.3M-GEN.IND.DIAM.USA. 1Q1 -6 x 3/8″ x-1-1/4 x=1-5/8″. D600Diamond Grinding Wheel. 1Q1 – 6 x 3/8″ x-1-1/4 x=1-5/8″. D600 – R75 –B1-5/8″.