Page 32 - HOLE MAKING CATALOG p185-310

USER GUIDE

Table 1
DEEP DRILLING - BTA SYSTEMChip Form General Information
Cutting speed: Vc (m/min)
50 70 90 110Chip form in deep hole drilling
Central
IntermediateChip form plays a key role in STS (Single tube system)
Peripheraland DTS (Double tube system) while large-volume and
high-pressure coolant do so as well. Because chips are Condition 0.10 0.15 0.20
removed through the tube with coolant, proper chip Feed: f (mm/rev)
formation is essential for smooth and steady evacuation.
From left to right in each box the order is central, intermediate and
Chip formation peripheral chip.

Chip formation is affected by multiple factors, such
as workpiece material, chipbreaker geometry, cutting
speed, feed, type of coolant, and coolant temperature.
Suitable chip formation depends on cutting operation
but is controllable by changing the cutting conditions.

How to decide the chip form

Generally the chip length should be 3 - 4 times
its width, but tends to be longer with difficult-to-cut
materials. In this case, chip evacuation can be
improved by making the chips thinner, which is
normally done by reducing the feed rate.

The graph below shows chip formation for different
cutting speeds and feeds. Short chips are created by
reducing the cutting speed or increasing the feed.

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