Self centering chucks are designed to
have all the jaws move in unison. The
jaws are driven by a spiral scroll when
the knurled ring is turned. Self
centering chucks will never duplicate
the accuracy that can be attained with
jaws that are moved independently, but
they will usually "get the job
done", saving a machinist much time
and effort.
The main purpose of a 4-jaw
self-centering chuck is to hold square
stock. It can also be useful in holding
thin wall round tubing that will
collapse easily. Round stock that is
held in this chuck must be perfectly
round and can not be at all elliptical
or one of the jaws will not grip. The
same is true for square stock; it must
be very square and not at all
rectangular to achieve a proper grip
with all four jaws.
This chuck is designed s that the
jaws can be removed and reversed to hold
larger stock. In the normal position,
stock from 3/32" (2.0mm) to
1-3/16" (30.16mm) can be secured.
With the jaws reversed, material up to
2-1/4" (56.0mm) can be held. The
hole through the center of the chuck is
.687" (17.46mm).
Click
for details