Общий каталог Sumitomo 2018 - 2019 - страница 568

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Parts of a Drill

Hight of point Margin width Margin Body clearance Flank Chisel edge angle Flute Land width Flute widthCutting edge Point

Cutting Outer corner angle

edge Chisel edge Chisel edge corner Depth of

Body clearance

Chisel edge length Relief angle Diameter of Body clearance

Leading edge Back taper Lead

Heel Helix angle Body clearance Rake face Flute length Overall length

Rake angle

Neck Tang Taper shank

Neck length Shank length

Straight shank Tang thickness

Tang length

B

Web thinning Web Cutter sweep

Point Angle and Force Min. Requirement Relief Angle

Point angle (small) Point angle (large) When point angle is large, thrust becomes

large but torque becomes small. * Large relief angle is needed at the center of the drill.

Web Thickness and Thrust Point Angle and Burr Effects of thinning

Thickness Feed rate (mm/rev)

Work : SS41Web thinning decreases the thrust concentrated
Cutting speed : 50m/minat chisel edge, makes the drill edge sharp and
When point angle is large, burr height becomesimproves chip control. Tool life is also longer.

low. Decrease Chisel Width by Thinning Typical types of thinning

A A : B or A/B = Flute width ratio

Width of Edge Threatment and

Cutting Force

8000 (N 6000 4000 2000 0

0,2 0,3 0,4

Feed rate (mm/rev) . m 60 (N 40

20 0

0,2 0,3 0,4

Feed rate (mm/rev) Drill: KDS 215 MAK Work material: C50 (230HB) Cutting conditions:

v = 50 m/min, Water soluble c

S type N type X type

S type : Standard type used generaly. N type : Suitable for thin web drills. X type : For hard-to-cut material or deep hole N13 drilling.