SCMT-431-HR Carbide Insert ~ HR- General Chipbreaker for Roughing, Stainless Steel Material ~ HR -M-class tolerance; suitable for both boring and O.D. roughing materials as steel, stainless steel and cast iron etc. ~ XAB749: Cutting edge with special strength and toughness, in an optimal combination with MT-TiCN, thick layer Al2O3TiN coating. ~ It is a suitable grade for a wide number of applications. ~ It is good for finishing, semi-finishing and light roughing of steel, cast steel and stainless steel. ~ ISO Insert No. SCMT120404HR ~ I.C. is 1/2" ~ L is 1/2" ~ S is 3/16" ~ d is 7/32" ~ r is .0157".