Perfect For DIY, Home and General Building/Engineering Using.Drill Bit Set For Stainless Steel, Steel, Copper, Iron, Aluminum, Wood And Plastic.M35 Cobalt High Speed Steel For Drilling Steel, Stainless Steel, Hard Metal and Iron. Alloyed with 5% Cobalt to improve heat resistance which will perform and outlast normal HSS bits.Perfect for drilling in tough metal, including heavy-duty abrasive alloy metal drilling on hardened steel. Adjustable cap regulates striking force.Brass body has a deeply knurled for nonslip control.Delivers an automatic spring-driven strike when pressed against .Can be used for vehicle emergencies as a side window glass breaking tool. light weight, aluminum center punch is perfect for marking a variety of materials.Marks workpiece with a dimple, creating a starting point that prevents screws and drills from wandering. Over length: 40~133mm Quantity: 15pcs per set Size: 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 8mm, 9mm, 10mm