The 5C back...
5C collets are a
very popular size in the machine shop. Sometimes, however, you may not have the
right size collet or you may need to hold a part that can only be held in a
4-jaw chuck. This chuck with a 5C back makes it possible to quickly change from
a collet to a chuck without breaking down your setup or changing to a different
machine. Simply remove the collet and insert this chuck into your 5C holder.
When done, change back to collets just as easily. This back has the standard 5C
taper, thread and keyway. Because it is CNC machined from a single billet of
steel, the back and body are concentric.
Diameter 4-Jaw Independent Chuck...
While collets are very accurate, each collet has a very small clamping range.
You may not always have the size collet you need for a job. A four-jaw chuck can also be used to hold irregularly shaped parts. With the use of a dial indicator, parts can be
centered with a great deal of accuracy. Four-jaw chucks can also be used to
deliberately hold a part off-center.
The stepped jaws
can be used to clamp either externally or internally, and the jaws are
reversible. The 3.1" (79 mm) 4-jaw chuck
is designed to grip from 3/32" (2 mm) up to 1.5" (38 mm) diameter stock with the jaws in the normal position. For larger diameters, the jaws must be reversed, and can grip up to 2.75" (70 mm). The chuck has a .79" (20 mm) through hole.
A P/N 3020 Sherline 5/32" hex T-driver (provided) is used to tighten each jaw
individually or to remove them for reversing.