H1/4" Impact screwdriver bits 1. S2 Steel 2. Sand blasting 3. Different size 4.58-60 hardness ... 1.Item: impact driver bits,impact screwdriver bits,power ... bits2.Size : H1/4"*25mm*PH33.Application: screwdriver bits, power bits, pneumatic power bitsS2 material4. ... hypophosphite both them available for us High quality sand blasting impact screwdriver bits