Wipe excess oil and metal shavings from
taps and tap wrenches.
Store in a case or wrap individually in
cloths to protect cutting surfaces.
Dies. Dies are used for cutting outside or male
threads on a rod, bolt, or pipe.
Types. The three types of dies commonly
used in the maintenance of Army aircraft are the solid,
adjustable-split, and pipe dies, shown in figure 4-104.
Solid dies. Solid dies, also called
rethreading dies, are used mainly for restoring damaged
or rusty threads on screws or bolts. They are available
in a variety of sizes for rethreading American Standard
Coarse and Fine threads. These dies are usually
hexagonal in shape and can be turned with a diestock,
socket, box-end, open-end, or any other wrench that will
Adjustable-split dies. Adjustable-split
dies can be used in either diestocks or machine holders.
These dies are either the screw adjusting type or the
open adjusting type.
adjustment in the screw-adjusting type is made by a
fine-pitch screw which forces the sides of the die apart
or allows them to spring together. This adjustment is
achieved by turning the adjusting screw clockwise to
increase thread diameter, and counterclockwise to
decrease the thread diameter.
adjustment in the open adjusting type is made by means
of three screws in the diestock; one for expanding and
two for compressing the dies.
Pipe dies. Two-piece rectangular
pipe dies are used to cut American Standard Pipe
threads. They are held in ordinary or ratchet diestocks.
The jaws of these dies are adjusted by setscrews. An
adjustable guide serves to keep the pipe in alignment
with the dies.
Uses. Male threads are cut on a piece of
stock by the following procedures.
Secure the work firmly in a vise.
Figure 4-104. Dies