Drill terminology and cutting characteristics Names of each part of drilling tools Straight shank with tang Shape specification and cutting charact

Drill terminology and cutting characteristics Names of each part of drilling tools Straight shank with tang Shape specification and cutting charact

Drill terminology and cutting characteristics Names of each part of drilling tools Straight shank with tang Shape specification and cutting characteristics Helix Angle Is the inclination of the flute with respect to the axial direction of a drill which corresponds to the rake angle of a bit. The rake angle of a drill differs according to the position of the cutting edge and it decreases greatly as the circumference approaches the centre.The chisel edge has a negative rake angle crushing the work. High-hardness material Small Rake angle Large Soft material (Aluminium etc.) Flute Length It is determined by depth of hole bush length and regrinding allowance. Since the influence on the tool life is great it is necessary to minimize it as much as possible. Point Angle In general the angle is 118 which is set differently to various applications. Soft material with good machinability Small Point angle Large For hard material and high-efficiency machining Web Thickness It is an important element that dete set according to applications. Small cutting resistance Low rigidity Good chip raking performance Machinable material rmines the rigidity and chip raking performa Thin Web thickness Thick nee of a drill. The web thickness is Large cutting resistance High rigidity Poor chip raking performance High-hardness material cross hole drilling etc. Margin The tip determines the drill diameter and functions as a drill guide during drilling. The margin width is determined in consideration of friction during hole drilled. Poor guiding performance Small Margin width Large Good guiding performance Diameter Back Taper To reduce friction with the inside of the drilled hole the portion from the tip to the shank is tapered slightly. The degree is usually represented by the quantity of reduction in the diameter with respect to the flute length which is approx. 0.04 0.1mm. It is set at a larger value for high-efficiency drills and the work material that allows drilled holes. Q024 TECHNICAL DATA TECHNICAL DATA