100-Piece Drilling Bit and Driving Accessories

The Carbide Square Drill Bit is the most widely used hole machining tool. The usual diameter range is 0.25 to 80 mm. Hardware Tool Step Drill Bit is mainly composed of Drill Bit working part and shank. The working part has two spiral grooves, shaped like a twist, hence the name. In order to reduce the friction between the guide part and the hole wall when drilling, the Chisel Concrete Drill Bit gradually decreases in diameter towards the shank and becomes an inverted cone. The screw Angle of twist drill mainly affects the size of cutting edge Angle, edge edge strength and chip removal performance, which is usually 25° ~ 32°. The spiral groove can be processed by milling, grinding, hot rolling or hot extrusion. The front edge of the Masonry Drill Bit will be grinded to form the cutting part. The cutting part of the Hammer Drill Bit has a vertex Angle of 118, a bevel Angle of 40° ~ 60°, and a back Angle of 8° ~ 20°. Due to structural reasons, the rake Angle is large at the outer edge and gradually decreases to the middle, and the transverse edge is negative rake Angle (up to about -55°), which acts as extrusion when drilling.