Civil Engineering Reference
In-Depth Information
Fig. 6.14 These tapered shapes are handles for a spanner. A standard socket is wel-
ded to the radiused end. The tapered handles are placed together so they make a
parallel that can be held in the vice to machine the diameter for the socket.
Clamping tapered work back to back
If you have two or more pieces of work with the same shallow taper, you can
clamp them back to back in the vice and, as long as the taper is quite shallow,
they will be held firmly.
Using 5C collets
There are some widely available collets called 5C, which are draw-in collets
designed to be used in a collet holder with a drawbar. They range from
3
⁄
64
in
to 1
1
⁄
8
in (metric collets are also available). You can also buy 5C collets to hold
square and hexagon shaped components.
A 5C 'emergency' collet can be obtained, which has no proper hole ma-
chined in it, just three rods, one between each slit. In use, you put a rod in
each of the slits, tighten up the collet, then you can machine a location in the
collet to take the work. The location can be any shape or size within the lim-
itation of the collet. To use the emergency collet, remove the three rods and
you can then tighten up the collet as normal.
There are expanding 5C collets where you can tighten a screw to expand
the collet to grip internal bores, and there are extra-large collets that can be
bored out larger than the 1
1
⁄
8
in standard collet.
