(b) Box wrench. Always select the size of wrench that fits the nut or
bolthead. Box wrenches will not slip off and are preferably used before open end
wrenches. A swing through an arc of 15 is sufficient to continuously loosen or
tighten a nut or bolt. Unless there is room to swing a box wrench in a full
circle, lift it completely off the nut when it comes to the limit of its swing and
place it in a new position which will permit it to be swung again. Since a box
wrench cannot slip off a nut, it is ideal for loosening tight nuts and bolts and
for setting them up. To set up means to give already tight nuts or bolts their
final tightening. After a nut is started, it can usually be worked more quickly
with an open end wrench than with a box wrench. For this reason, combination box
and open end wrenches are very popular and more convenient-the box end to break
loose or set up and the open end to do the actual turning.
(c) Socket wrenches. To use a socket wrench, select the size of socket
that fits the nut or bolt to be turned and push it onto the handle which is best
suited to the job. If there is room to swing it, use the ratchet handle. The
handle may be made to ratchet in one direction for tightening and in the other
direction for loosening work. It is necessary only to swing the handle back and
forth in order to turn the nut in the desired direction. The socket need not be
raised from the nut at the end of each swing. A nut spinner handle (fig 7) also
saves time. When a tight nut is to be loosened or a nut is to be set up, the
handle can be swung at right angles to the socket to provide the most leverage. At
the point where the nut turns easily, the handle can be swung to a vertical
position and twisted rapidly between the fingers in the same manner as a
screwdriver. A universal joint socket wrench (fig 6) makes it possible to turn
nuts where a straight wrench could not be used unless some part of the machine or
equipment is removed.
(d) Key (Allen) setscrew wrenches. Select the proper type and size that
fits the recess of the screw being worked on. The short end of the wrench is used
to give a final tightening or break loose tight screws. The long end of the wrench
is used to turn the screw rapidly when very little leverage is needed.
(e) Adjustable open end wrench. Always place the wrench on a nut or
bolt so that the force used to turn it is applied to the stationary jaw side of the
wrench (fig 15). After placing the wrench in position, tighten the knurled
adjusting nut until the wrench fits the nut or bolthead as tightly as possible. If
it does not fit tightly, it will slip, which may result in an injury to your hand
and may also round the corners of the nut or bolthead.
(f) Auto and monkey wrenches. Use the auto or monkey wrench in the same
manner as you would the adjustable open-end wrench.
Always place the wrench on a nut or bolt so that the turning force is
applied to the back of the handle; that is, the side of the wrench
opposite the jaw opening (fig 15).
Using adjustable wrenches.