Sure-Grip® Power Chuck

Sure-Grip ® Power Chuck Safety and Technical Manual B-87Z
Other Cutting Force Calculations
We have illustrated that it is important to make certain that the draw bar force and the gripping force is adequate to safely
grip your workpiece. Loss due to centrifugal force must always be taken into consideration. These losses are due to RPM,
jaw height & mass and workpiece configuration. The jaw force must be adequate to grip the part during the cutting
operations as illustrated by the turning example.
There are many other types of machining operations such as drilling, tapping, broaching, facing, cutoff, knurling, threading,
grooving and skiving which exert force on the chuck. The cutting tool rake angles and design configurations affect the
gripping force of the chuck differently. It is beyond the scope of this publication to be able to cover all the cutting forces
and torques generated by the various types of tools made by hundreds of manufacturers.
The user of this chuck must acquire and thoroughly understand the technical report ISO # TR-13618 "Code of Practice
for Safe Operation of Work Holding Chucks Used on Lathes" published by the American National Standards Institute
(ANSI). This publication covers the formulas necessary to calculate the forces acting upon the chuck assembly allowing
the user to determine if the workpiece is safely held by the chuck. The "Machining Data Handbook" by Machinability Data
Center (Metcut Research Association Inc.) has tables giving the torque and force requirements of most styles of tooling
used on a lathe. Tool manufacturers such as Kennametal, Valenite, Iscar, and others have publications which relate to their
specific tooling.
It is the responsibility of the user to make certain that the workpiece is safely gripped by the chuck.
Hardinge Inc. One Hardinge Drive, Elmira, New York U.S.A. 14902-1507 800.843.8801 www.hardingetooling.com
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