Общий каталог Mitsubishi 2020 - 2021 - страница 1747

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TECHNICAL DATA DRILL TERMINOLOGY AND CUTTING CHARACTERISTICS y CUTTING EDGE GEOMETRY AND ITS INFLUENCE As shown in table below, it is possible to select the most suitable cutting edge geometry for different applications. If the most suitable cutting edge geometry is selected then higher machining efficiency and higher hole accuracy can be obtained. a Typical Cutting Edge Geometries Grinding Name Geometry Features and Effect Use • The flank is conical and the clearance angle • For general use. increases toward the center of the drill. Conical • The flank is flat and facilitates cutting. • Mainly for small diameter drills. Flat • As there is no chisel edge, the results are high • For drilling operations Three Rake centripetal force and small hole oversize. that require high hole• Requires a special grinding machine.accuracy and positioning Angles • Requires grinding of three sides. accuracy. • To increase the clearance angle near the center • For drilling that requires of the drill, conical grinding combined with high accuracy. Spiral Point irregular helix. • S type chisel edge with high centripetal force and machining accuracy. • The cutting edge is ground radial with the aim of dispersing • For cast iron and light load. alloy. Radial Lip • High machining accuracy and finished surface roughness. • For cast iron plates. • For through holes, small burrs on the base. • Steel • Requires a special grinding machine. • This geometry has two-stage point angle for • For thin sheet drilling. Center Point better concentricity and a reduction in shockwhen exiting the work material. Drill y WEB THINNING The rake angle of the cutting edge of a drill reduces toward the center, and it changes into a negative angle at the chisel edge. During drilling, the center of a drill crushes the work, generating 50 ─ 70% of the cutting resistance. Web thinning is very effective for reduction in the cutting resistance of a drill, early removal of cut chips at the chisel edge, and better initial bite. Geometry P X type XR type S type N typeThe thrust load substantiallyThe initial performance isPopular design, easy cuttingEffective when the web is reduces, and the bite slightly inferior to that of the X type. comparatively thick. Features performance improves. This type, but the cutting edge is is effective when the web is tough and the applicable range thick. of work materials is wide. Major General drilling and deep hole General drilling and stainless General drilling for steel, cast Deep hole drilling. Applications drilling. steel drilling. iron, and non-ferrous metal. P032 TECHNICAL DATA