Technical Information

Technical Information
Technical Information
Balancing
Balancing
Kennametal offers a range of balanced and balanced-by-design
toolholders capable of extending spindle and tool life and improving
part quality at higher machining speeds.
Definitions for Balance
Standard Toolholder
A toolholder that may contain uncorrected features (unbalanced drive slots,
notches, locking screws, etc.). Standard toolholders have no compensating
features added to correct balance, used in basic, low-speed applications.
Balanced-by-Design
A toolholder designed with compensating features to correct any unbalance
caused by uneven drive slots, notches, locking screws, etc. The balanced
toolholder is capable of being used in high-speed applications. Small, residual
unbalance may result due to normal manufacturing tolerances within the shank
standards.
When machining at higher speeds, responsible machining practices must
be observed. Unbalance is caused by uneven mass distribution in the tool
or toolholder. Potential sources of unbalance are movable parts (adjustable
cartridges, set screws, spindle spring pack, and clamping mechanisms),
manufacturing tolerances, and design.
Balanceable
A toolholder with a built-in mechanism that can adjust to correct any
unbalance inaccuracies incurred during normal manufacturing. The fully
assembled tool (toolholder and cutting tool) can be balanced as a system
using a balancing device.
Balanced
A toolholder has been balanced to predetermined specification after manufacture
by checking the balance condition with a balancing device. This may be followed
by physically removing material from the toolholder, such as holes and/or slots.
Forces caused by unbalance increase with the rotational speed squared.
Excessive unbalance can cause premature wear to the tool and spindle bearing,
which can adversely affect surface finish and accuracy.
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