... : 65Mn steel Size: 150mm-350mm Hardness: HRC48-55 Stone chisel with square rubber grip 1. Material: 65Mn alloy steel, or Chrome Vanadium ... steel, or High Carbon steel. 2. Drop forged and heat treated.3. Hardness: HRC48-55.4. Shank: Hexagoanl, octagongal ... , 400x18mm, 250x19mm, 300x19mm, 350x19mm, 250x22mm, 300x22mm, 250x25mm, 300x25mm Stone chisel with square rubber grip