(Facom Tools Ltd)
Figure 3.36 Straight and offset ring spanners
(Facom Tools Ltd)
Combination spanner
The combination spanner has an open-ended jaw at
one end and a ring on the other end. Both ends are
the same size. The combination is probably the
best choice of second set, for it complements either
open-ended spanner or ring spanner sets. Combination
spanner sets are available in AF in to in
and metric 3.2 mm to 32 mm (Figure 3.37).
Hand and power tools 107
Adjustable wrench
An adjustable wrench has one fixed jaw and one
movable jaw. The movable jaw is adjusted by
means of a worm wheel fitted in the handle, which
is meshed with teeth in the jaw. These wrenches
are useful because they are manufactured in a
range of sizes and each one can be adjusted to fit
many sizes of nuts (Figure 3.38).
Socket sets
In many situations a socket ratchet is much faster
and easier to use than an open-ended or ring spanner
because of its versatility in use, and in some body
repair applications it is absolutely essential. A basic
socket ratchet set consists of a ratchet, bar extensions,
a universal joint and a set of sockets (Figure 3.39).
Figure 3.37 Combination and offset combination
spanners (Facom Tools Ltd)
Figure 3.38 A range of adjustable wrenches ( Facom
Tools Ltd)
Figure 3.39 Socket set (Facom Tools Ltd)
The barrel-shaped socket fits over and around a
given size of nut; inside it is shaped like the ring
spanner, having a set of teeth to grip the points
of the nut. Sockets are available with 6 pointed
teeth and 12 pointed teeth. A 6-point socket gives a
tight hold on a hex nut, minimizing slippage and
rounding of the nut’s points. The 12-point socket
does not have the holding power of the 6-point
socket, but its numerous positions maximize the
possible turning radius (Figure 3.40a).
The closed end of the socket has a square
hole into which the drive shaft of the ratchet fits
(Figure 3.40b). Socket sets can be purchased in,,
and in drive sizes. The smaller drive sizes are
used for turning small fasteners, badges and trim
where little torque is required. The larger drive
sizes with the corresponding longer handles are
used where greater torque is needed. A body
repairer will need sets of, and in drive sockets.
The size of the individual sockets in a set
depends on the drive size of the set as well as the
number of sockets in the set. The socket size is
108 Repair of Vehicle Bodies
the same as the face-to-face dimension of the bolt
it fits. A in set has sockets ranging from to in
(5 to 18 mm), whereas a in socket set has sockets
ranging from to in (13–40 mm).
Sockets are available not only in standard faceto-
face diameters, but also in various lengths or
bore depths. Normally the larger the socket size, the
deeper the well. Deep well sockets are made extra
long for reaching nuts or bolts in limited access
areas (Figure 3.40c).
Socket set accessories
Socket set accessories multiply the usefulness of
the socket set. A good socket set has a variety of
accessories such as:
Ratchet
Ratchet attachment
Extension bars
Speed brace
Long-hinged handle with universal joint
Sliding T-bar
Universal joint
Flexible spinner
Flexible extension
Coupler.
Screwdriver attachments
Screwdriver attachments are also available for use
with socket ratchets. These attachments are very
useful when a fastener cannot be loosened with
a regular screwdriver owing to lack of access
and space. The leverage that the ratchet handle
provides is often all it takes to move a stubborn
screw.
Screwdrivers
A variety of threaded fasteners used in the automotive
industries are assembled by the use of a
screwdriver. Each fastener requires a specific kind
of screwdriver, and a body repairer should have
several sizes of each type.
All screwdrivers, regardless of type, are designed
to have several things in common. The size of the
screwdriver is determined by the width or diameter
of the blade and the length of the shank. It is
important to select the blade tip accurately by
matching it to the size of the slot or the type of
fastener being used. The larger the handle, the
better the grip and the more torque it will generate
when turned.
Standard screwdriver (for slotted heads)
A slotted screw accepts a screwdriver with a
standard tip. The standard tip screwdriver is probably
the most common type used. The blade should
match the slot: an oversize screwdriver will not
(a)
(b)
(c)
Figure 3.40 (a) Standard sockets (b) ratchet with
in drive (c) standard and deep well sockets (Facom
Tools Ltd)
Hand and power tools 109
reach the bottom of the slot and an undersize
screwdriver will float in the slot, and either condition
could result in damage to the tool and the
fastener.
Phillips screwdriver (for cross-heads)
Phillips screws have a four-pronged funnel-shaped
depression in the screw head, and are known as
cross-heads. The tip of the Phillips screwdriver has
four prongs that fit the four slots in the screw head.
The four surfaces enclose the screwdriver tip so
that there is less likelihood that the screwdriver
will slip off the fastener. The most useful set of
Phillips screwdrivers ranges from number 0 to
number 4.
Pozidriv screwdriver
This screwdriver is like a Phillips in that the head
is in the form of a cross, but the tip is flatter
and blunter. The square tip grips the screw head
and slips less than a Phillips screwdriver. Although
Pozidriv and Phillips look alike, they are not
interchangeable. The most useful set of Pozidriv
screwdrivers ranges from number 1 to number 4.
Torx screwdriver
The Torx fastener is used quite a lot on vehicle
bodies. The screwdriver has a six-pronged star
profile which provides greater turning power and
less slippage, and also ensures optimum pressure
to prevent the tool from slipping out of the fastener’s
head.
Speciality screwdrivers
These are normally in sets of screwdriver tips and
assorted drivers which are all interchangeable and
prove most useful in vehicle body repair work.
Toolchests
A cabinet-type toolchest as shown in Figure 3.41 is
standard equipment in most body shops. A portable
toolbox on top of the chest holds large hand and
power tools. A chest of drawers holds spanners,
sockets and all the necessary assembly tools. The
toolchest is on castors so that it can be conveniently
located in any working area of the body
shop.
Figure 3.42 shows a complete set of all assembly
tools.
3.18 Power tools used in body repair work
Choosing between pneumatic or electric power
tools has always been difficult because, while they
are designed to perform basically the same function,
the particular advantages and disadvantages
of each are so different.
Electric tools are simple to set up. They require
only a source of electric current, and so are suitable
for immediate use anywhere in the workshop.
The disadvantage is that because they have their
own power supply (the motor) incorporated, they
tend to be heavy and awkward for some jobs. Not
only that, but over-heavy use can wear the motor,
causing it to burn out.
Pneumatic tools, by contrast, are more complex.
Among the advantages they offer are the regulation
of air flow to suit the job, and the fact that they are
Figure 3.41 Portable toolchest (Facom Tools Ltd)
110 Repair of Vehicle Bodies
usually lighter, smaller and easier to handle. They
also require less maintenance than a comparable
electric tool. These factors can only be achieved,
however, if a high-performance air compressor
system is available. Moreover, it has long been
a disadvantage that, despite filters and regulators,
peneumatic tools can still blow oil, rust, dust and
other impurities into the atmosphere and on to the
work being treated.
Power tools play an important part in the
modern techniques used by the panel beater in the
repairing of crash damage to motor vehicles. Their
use reduces man hours to a minimum and they also
enable the operators to achieve better results than
those possible using hand tools. A wide range of
equipment is available to suit all types of crash
damage.
Section 3.19 to 3.25 describe the typical range of
power tools.
3.19 Air power chisel
This tool (Figure 3.43) is designed for the removal
of damaged panels so that essential stripping can
be carried out easily and quickly. It consists of a
chisel bit which is retained by a spring through one
end of a barrel, and a piston which moves to and
fro within the barrel, striking the end of the chisel
bit as it does so. The barrel must be kept dirt-free
to eliminate the possibility of undue wear by the
reciprocating movement of the chisel. A featheraction
trigger in the handle allows for variation in
the strength of the blow according to the amount of
pressure applied. To provide additional safety a
beehive or volute spring is fitted over the end of
the barrel to prevent the chisel leaving the tool
accidentally.
A wide range of special chisel bits is produced
for the power tool. Most of these are cutting chisels
of various sizes, used for general dismantling,
cutting rivets, nuts, bolts and the removal of spotwelded
sections. There is also a special thin-gauge
metal cutting chisel for use on panel work, and a
recessing tool which can be fitted on the end of the
chisel. The recessing tool can be used on the edges
of panels to form a lip or joggled section so that
one panel passes over the face of the other, forming
a flush finish which is ideal for spot-weld connections
and joints in panels.
3.20 Metal cutting shears and nibblers
Metal shears
These are usually electrically operated (Figure
3.44), but in some cases can be driven by compressed
air (Figure 3.45). They are designed to be
used in the hand with an on/off trigger control
built in the handle. The blade holding shoe is
designed in a spiral so that it parts the metal as it
cuts it. The machine is based on the principle of
shearing metal, and this is done by a pair of very
narrow blades, one of which is usually fixed
while the other moves to and fro from the fixed
blade at high speed. The blades have a very pronounced
angle or set to permit the blade to pierce
the sheet for internal cutting. The tool can be easily
turned when cutting owing to the narrow
width of the blades, and so can cut curved as well
as straight shapes. The shears are capable of
cutting sheet metal up to a maximum of 2 mm
