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GENERAL INFORMATION
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An open-end wrench is fast and works best in areas
with limited overhead access. It contacts the fastener at
only two points and is subject to slipping if under heavy
force, or if the tool or fastener is worn. A box-end wrench
is preferred in most instances, especially when braking
loose and applying the final tightness to a fastener.
The combination wrench has a box-end on one end
and an open-end on one end and an open-end on the
other. This combination makes it a convenient tool.
Adjustable wrenches
An adjustable wrench or Crescent wrench (Figure 6)
can fit nearly any nut or bolt head that has clear access
around its entire perimeter. An adjustable wrench is best
used as a backup wrench to keep a large nut or bolt from
turning while the other end is being loosened or
tightened with a box-end or socket wrench.
Adjustable wrenches contact the fastener at only
two points, which makes them more subject to slipping
off the fastener. Because one jaw is adjustable and may
become loose, this shortcoming is aggravated. Make
certain the solid jaw is the one transmitting the force.
Socket Wrenches, Ratchets and
Handles
Sockets that attach to a ratchet handle (Figure 7)
are available with 6-point or 12-point openings (Figure 8)
and different drive sizes. The drive size indicates the
size of the square hole that accepts the ratchet handle.
The number stamped on the socket is the size of the
work area and must the fastener head
As with wrenches. a 6-point provides
superior-holding ability. While a 12-point socket needs to
be moved only half as for to reposition it on the fastener
Sockets are designated for either hand or impact use.
Impact sockets are made of thicker material for more
durability. Compare the size and wall thickness of a
19-mmhand socket (A, Figure 9) and the 19-mm impact
socket (B). Use impact sockets when using an impact
driver or air tools. Use hand sockets with hand-driven
attachments
