USE/CARE OF HANDTOOLS & MEASURING TOOLS - OD1621 - LESSON 2/TASK 1
(b) Box Wrenches. Box wrenches (figure 16) are so named because
they completely surround or box the bolt head or nut. The opening in a box
wrench contains 6 or 12 notches, called points, arranged in a circle. The
box wrench is a safer tool than the open-end wrench, since it will not slip
off the work.
As little as one-twelfth of a turn can be taken at each
stroke, if necessary in close quarters.
Box wrenches may have straight
handles, they may be offset, or the box end may be offset. Box wrenches are
available in the same sizes as are open-end wrenches ((a) above) and usually
have two openings; one opening, 1/16 inch larger than the other.
Some
openings may be 1/32 or 1/8 inch larger than the other.
A ratchet box
wrench (not illustrated) usually has two 12-point openings and is not
automatically reversible. However, it can be turned around to perform both
tightening and loosening operations.
Being of sturdy, thin construction,
they are convenient for working in limited spaces. Ratchet box wrenches are
issued in four sizes, ranging from 3/8 and 7/16 inch openings to 3/4 and 7/8
inch openings.
FIGURE 16.
BOX AND COMBINATION WRENCHES.
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