Introl Viruta

Technical Reference

Chipbreaker
Factors affecting chip control
• Of these, feed has the greatest effect followed by depth of cut and cutting speed in order listed. • Feed is proportionate to thethickness of chips. • Depth of cut is proportionate to the width of chips. • There are optimum values (effective range) in feed and depth of cut. • Cutting speed is in inverse proportion to chipthickness. Effective range becomes narrow at high speed.
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Depth of cut (mm)

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(1) Cuttingcondition 1 Feed 2 Depth of cut 3 Cutting speed

Effecttive range

Feed (mm/rev)

(2) Workmaterial 1 Alloy element 2 Hardness 3 Heat treatment condition

• These are related to thickness of chips and ease of curling. • Mild steel chips are thicker than those of hard steel. • Hard steel chipsare liable to curl more than those of mild steel. • Chips that do not curl are thin. As an exception, in case of mild steel even if thick, may not curl.

Depth of cut (mm)

Mild Steel

Hard steelFeed (mm/rev)

(3) Tool geometry 1 Side cutting edge angle 2 Nose radius

• Side cutting edge angle is relative to chip thickness and width • Side cutting edge angle is preferably small. • Noseradius is relative to thickness and width and the direction of flowing out. • In finishing, small nose radius, while for rough cutting, large nose radius is better.

Depth of cut (mm)S.C.E.A:large S.C.E.A:small Nose radius:small Nose radius:large

Feed (mm/rev)

(4) Shape of chipbreaker 1 Rake angle 2 Chipbreaker width 3 Chipbreaker depth

• Rake angle is in inverse proportion to chipthickness. • Depending on the work material, there is an optimum value. • Chipbreaker width is selected proportionately to feed. • Narrow at low feed and wide at high feed. • Chipbreaker depth is to beselected so as to be inversely proportionate to feed. • Deep at low feed and shallow at high feed.

Depth of cut (mm)

Rake angle:large Rake angle:small Breaker width:small Breaker width:large...