Description: This Step Drill Bit is made of high speed steel, durable for use. Widely used to cut holes in a variety of material including steel, brass, wood, plastic, etc. Ideal for DIY, family, general building, and engineering. Features: Suitable for cutting various materials, including steel, brass, wood, plastic, etc. Nitrogen coated to reduce friction and run cooler. Large bit has 3 sided shank, which can prevent drop. Faster, smoother and cleaner cutting, every step had a clear diameter of depth. Ideal for DIY, family, general building, and engineering. Specification: Material: HSS Surface treatment: nitrogen Size: Approx. 102*31.7mm / 4.0*1.2inch(4-32mm), 73.7*19.7mm / 2.9*0.8inch(4-20mm), 64.4*11.4mm / 2.5*0.4inch(4-12mm) Weight: 228g Package Included: 1 x 4-12mm Step Drill Bit 1 x 4-20mm Step Drill Bit 1 x 4-32mm Step Drill Bit 1、Suitable for cutting various materials, including steel, brass, wood, plastic, etc. 2、Nitrogen coated to reduce friction and run cooler. 3、Large bit has 3 sided shank, which can prevent drop. 4、Faster, smoother and cleaner cutting, every step had a clear diameter of depth. 5、Ideal for DIY, family, general building, and engineering.