Page 1027 - Tungaloy Catalog

Technical Reference
Chipbreaker
Factors affecting chip control

• Of these, feed has the greatest effect Vc = 100 SFM Vc = 200 SFM
followed by depth of cut and cutting speed.
(1) Cutting conditions • Feed is proportionate to the thickness of
chips.
1 Feed • Depth of cut is proportionate to the width of
2 Depth of cut chips. Depth of cut: ap (in) Effecttive
3 Cutting speed • There are optimum values (effective range) in range
feed and depth of cut.
• Cutting speed is in inverse proportion to chip
thickness. Effective range becomes narrow
at high speed.
Feed: f (ipr)

• These are related to thickness of chips
and ease of curling. Mild steel Hard steel
(2) Work material • Mild steel chips are thicker than those of
1 Alloy element hard steel.
2 Hardness • Hard steel chips are liable to curl more Depth of cut: ap (in)
3 Heat treatment than those of mild steel.
condition • Chips that do not curl are thin. As an
exception, chips cut from mild steel may
not curl due to thickness. Feed: f (ipr)

• Side cutting edge angle is relative to chip S.C.E.A: small S.C.E.A: large
thickness and width Nose radius: small Nose radius: large
(3) Tool geometry • Side cutting edge angle is preferably
1 Side cutting small.
edge angle • Nose radius is relative to thickness and Depth of cut: ap (in)
2 Nose radius width and the direction of flowing out.
• In finishing, small nose radius, while for
rough cutting, large nose radius is better.
Feed: f (ipr)

• Rake angle is in inverse proportion to chip Rake angle: small Rake angle: large
thickness. Breaker width: small Breaker width: large
(4) Shape of chipbreaker • Depending on the work material, there is Breaker depth: large Breaker depth: small
an optimum value.
1 Rake angle • Chipbreaker width is selected Depth of cut: ap (in)
2 Chipbreaker width proportionately to feed.
3 Chipbreaker depth • Narrow at low feed and wide at high feed.
• Chipbreaker depth is to be selected so as
to be inversely proportionate to feed.
• Deep at low feed and shallow at high feed. Feed: f (ipr) Technical Reference

• Effective range is wider with wet cutting.
Depth of cut: ap (in) 14
• Chips are liable to curl especially at low Wet cutting Dry cutting
feed range.
(5) Cutting fluid

Feed: f (ipr)

• The machine has enough power and
(6) Machine mechanical strength.
1 Strength
2 Power limit • Select the machine consistent with the
size of work material to be used.

14–9