1. Shank
2. Body
3. Point
4. Tang
5. Neck 1. Shank Normally drills up to 1/2 or 13 mm in diameter contain directly shanks as those over this diameter generally contain taper shanks. Drills are presented by straight shank taper shank and shank by a tang. Shank also straight or tapered, is use to hold the drill in drilling machine. Straight shank drills are held in a drill chuck. Taper shank drills are held in taper hole of drill press spindle directly or by with drill sleeve of proper size. 2. Body Body is part of drill among shank and point. It consists of number of parts explain under. a. Body clearance Body clearance is undercut piece of body among margin and flutes. It’s prepared smaller to decrease friction among drill and hole through drilling process. b. Web Web is skinny part in center of drill which extends full length of fluid. This part forms chisel edging at the cutting end of drill. The web regularly increases in thickness towards shank to give drill power. c. Margin Margin is thin raised section on body of drill. It is instantly next to flutes with extends along whole length of fluid. Its function is to give a full size to drill body with cutting edges. d. Flutes Flutes are two or more helical grooves cut about body of drill. They as of the cutting edges confess cutting fluid and permit chips to escape as of hole. 3. Point Point of a twist drill consists of chisel edge lips, lip clearance with heel. a. Lips Cutting edges are fund by the joint of flutes. The lips have to be of the same length with containing the same angle so-that the drill will run proper. b. Lips clearance Relief ground on point of drill extends as of the cutting lips back to heel. Standard lip clearance is from 8 to 121) depending on rigidity or smoothness of objects. c. Chisel edge Chisel edge is the chisel shaped part of drill point. 4. Tang The end taper part of drill bit is called tang. 5. Neck Neck separates the body and shank. Its undersize diameter piece is use to number punch size (diameter) of drill.
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