Short note on:

i) Nomenclature of drilling tool.

ii) Geometry of milling cutter

Mumbai University > Mechanical Engineering > Sem 4 > Production Process II

Marks: 5M

Year: Dec 2014

i) Nomenclature of drilling tool.

.Following are the twist drill elements

Body Clearance: The portion of the body which is reduced in diameter to give diametric clearance . Face: The portion of the flute surface adjacent to the lip on which the chip impinges as it is cut from the work.

Flank: The surface on the drill point which extends behind the lip to the following flute.

Flutes: The grooves in the drill body which provides lip and is useful for allowing the chip to escape, to cause the chip to curl and to permit the cutting fluid to reach the cutting edge.

Heel: The edge formed by the intersection of the flute surface and body clearance.

Lands: The cylindrically ground surface on the leading edges of the drill flutes.

Lip (Cutting edge): The edge formed by the intersection of the flank and face . Shank: The part of the drill by which it is held and driven.

Body: The portion of the drill extending from its extreme point to the commencement of neck.

Axis: The longitudinal centre line of the drill.

ii) Geometry of milling cutter

Principal part in the geometry of a plain milling cutter

Body of cutter: The part of the cutter left after the exclusion of the teeth and the portion to which the teeth are attached.

Cutting Edge: The edge formed by the intersection of the face and the circular land or the surface left by the provision of primary clearance.

Face: The portion of the gash adjacent to the cutting edge on which the chip impinges as it is cut from the work.

Fillet: The cured surface at the bottom of gash which joining the face of one tooth to the back of the tooth immediately ahead.

Land: The part of the back of tooth adjacent to the cutting edge which is relived to avoid interference between the surface being machined and the cutter.

Lead: The axial advance of the helix of the cutting edge in one complete revolution of the cutter.

Outside diameter: The diameter of the circle passing through the peripheral cutting edge.

Root diameter: The diameter of the circle passing through the bottom of the fillet.

Relief angle: The angle in a plane perpendicular to the axis which is the angle between the land of a tooth and the tangent to the outside diameter of cutter at the cutting edge of that tooth.

Rake angle: The angle measured in the diametric plane between the face of the tooth and a radial line passing through the tooth and a radial line passing through the tooth cutting edge.

Lip angle: The included angle between the land and the face of the tooth, or alternatively the angle between the tangent to the back of the cutting edge and the face of the tooth.

Helix angle: The cutting edge angle which a helical cutting edge makes with a plane containing the axis of a cylindrical cutter.