Carbide drill bits
carbide drill bits are a kind of tool to drill round hole of workpiece through its relative fixed axis rotary cutting. It is named for its spiral shaped chip holding groove. Spiral groove has two grooves, three grooves or more, but two grooves are the most common. Twist drill can be clamped on hand or electric hand-held drilling tools or drilling machines, milling machines, lathes and even machining centers. The drill bit is usually made of high-speed tool steel or cemented carbide. any requirements, please let us know.
Carbide drill bits compositoin
Standard twist drill. Twist drill consists of shank, neck and working part
(1) The diameter of the twist drill is limited by the hole diameter. The spiral groove makes the drill core thinner and the drill bit rigidity is low; there are only two ribs to guide, the axis of the hole is easy to deviate; the chisel edge makes the centering difficult and the axial resistance increases. Large, the drill is easy to swing. Therefore, the shape and position error of the drilled hole is relatively large.
(2) The rake face and flank face of the twist drill are both curved surfaces, and the rake and relief angles of each point along the main cutting edge are different, and the rake angle of the chisel edge is -55°. The cutting conditions are poor; the distribution of cutting speed along the cutting edge is unreasonable, and the cutting edge with the lowest strength has the highest cutting speed, so the wear is serious. Therefore, the precision of the processed hole is low.
(3) The full edge of the main cutting edge of the drill bit participates in cutting, and the cutting speed of each point on the edge is not equal. It is easy to form spiral chips and difficult to remove chips. Therefore, the chip and the hole wall are squeezed and rubbed, which often scratches the hole wall, and the surface roughness after processing is very low