Page 1042 - Tungaloy Catalog

Technical Reference
Drilling Tools
d Chip shape produced with peripheral insert
• Chip problems such as entangling are mainly caused by chips pro-
duced with the peripheral insert. These problems are dependent
on the types of work material and the cutting conditions.
• As shown below, when the feed is extremely low, the chips jump
over the chipbreaker groove and the continuously long chips may
wrap around the drill body.
• When the feed is too high, the chips increase in thickness and can
not be curled.
• Therefore, it is important to select proper cutting conditions to suit
the machining so that well controlled chips will be formed.

Medium to high carbon steels, alloy steels, etc.

As shown below, several turns of coil are an ideal shape.
As the feed increases, the curl radius and the number of turns tend to decrease.

d Typical chip shapes of general steels d Variation of chip shapes relating to feeds

f = .003 ipr f = .004 ipr f = .005 ipr

Stainless steels, low-carbon steels, low-alloy steels, etc.
• When machining long-chip materials such as stainless steels and mild steels, the wrong selection of cutting conditions results
in chip entangling and tool breakage at worst. Therefore, cutting conditions should be carefully selected.
• “C” shaped, continuous coils of several to ten turns having adequately divided lengths are the ideal shape.

d Ideal chip shapes
Stainless steel (JIS SUS 304) Mild steel (JIS SS400) For machining stainless steels or low carbon steels,
( ø22, Vc = 3.93'' SFM, f = .0003'' ipr ) ( ø22, Vc = 6.29'' SFM, f = .003'' ipr )
DS chipbreaker is recommended.
chipbreaker
When using a TDX drill in tool rotating condition, DS
Technical Reference DJ chipbreaker stable machining than DJ chipbreaker. When using
DS
chipbreaker produces compact chips and allows more
it in work rotating condition, DS chipbreaker pro-
vides outstanding affect on chip control.

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