Square tool holder is made of high quality steel with heat treatment and black surface treatment. Size is 16mmX16mm inserts made of carbide with high-end composite coating R0.4. They can machine carbon steel, steel, stainless steel, cast iron and other metals. 1616-6,1616-7.1616-8,1616-10 1PCS S06-SCLCR06, S07-SCLCR06, S08-SCLCR06, S10-SCLCR06 1PCS CCMT060204 10PCS.