DCMT Turning Inserts 55° Rhombic Insert Insert Grades QX5030 (ISO P20-P40 M20-M30) CVD Coated. - Medium / rough turning and intermediate cutting of steel / stainless steel. Combination of toughest substrate and alumina coating (MT-TiCN + TiC + AL2O3 + TiN) having superior chipping resistance provide wide coverage. Chip Breaker: PM. Application: Med Cut.