This document discusses different types of vices used in engineering and metalworking, including engineers vices, hand vices, and leg vices. It also covers pipe bending and factors that affect how easily pipe can be bent, such as bend radius, pipe diameter, wall thickness, and metal composition. Proper use of pipe benders and techniques like checking bend angles and allowing for springback are also outlined.

1. Bench vices
• A variety of engineer’s and fitters vices are
available for different classes of work. Most
vices are made out of cast iron or steel and
will give good service, provided that it is not
used as an anvil. Steel vices are much stronger
but are more costly.

2. • Vices are fitted with
hardened steel jaw faces
screwed in place and
these are either smooth
faced or serrated,
depending on the work
being done. The serrated
jaws grip firmly but mark
the work unless vice
clamps are used.
•

3. • In the mechanic’s vice the screw passes
through a solid nut and all adjustments must
be made by turning the screw to hold a work
piece securely as operations are carried out on
it

4. Hand vice
• These are the most
convenient tools for
holding small work on
the drilling machine or
for holding small parts
for small jobs. Hand
vices are measured over
the length and range
between 100mm to
150mm.

5. Hand vice
• The hand vice is a very useful tool for holding
small pieces of work that cannot be held in
the engineer’s vice or in the hands.
• The leg vice is an older form of vice which is
used for heavy work. It is made out of mild
steel with cast steel jaws. It has a long leg that
touches the ground.

6. • The parts, especially the handle and screw, are
heavier than those of the engineers vice. The
leg vice does not have quick release levers.
Although it is strong, its greatest disadvantage
is that the jaws are only parallel in one
position, which makes gripping of work
difficult. This difficulty is the main reason why
the engineers vice was designed.
•

7. BENDING
• Bending is the controlled
deformation of metal to a
required shape. Many
different forms of metal
can be bent such as steel
tube, rod, flat band and
box section. To control
the size and shape of the
bend simple bending
tools can be made in the
workshop.

8. Pipe bending
• A pipe-bending
machine is a very useful
tool in a workshop.
Bent tube is used in
wheelchairs, and many
other common items of
furniture such as chairs
or hospital beds shown
in figure

9. Pipe bender
• The pipe bender consists of the following
parts:
• Former
A former is a shape that the pipe is bent
around. The former dictates the radius and
shape of the bend.

10. Bending
• Follower
• The follower pushes the
tube against the former.
Its shape is made to fit
the pipe to be bent so
that the pipe does not
crush with the force of
bending.

11. Bending
• Lever or handle
• The lever assists the
bending action. The
longer the lever, the
easier it will be to make
the bend. The source of
power may be manual,
electric or hydraulic.
•

12. • Roller
•
• The roller rolls along the
back of the follower as
the lever is pulled, and
keeps the follower tight
against the tube. If there
is a small gap between
the follower and the
roller, the pipe will not
bend as tightly, but it will
be easier to bend.

13. Factors affecting pipe bending
• Bend radius: Smaller radiuses will require
much more force to bend, as there will be a
large amount of deformation. Larger radiuses,
for example a wheelchair pushrim, may not
need to be bent with a follower.
• Pipe diameter: Smaller diameter pipes will be
able to be bent to smaller radiuses.
•

14. • Pipe wall thickness: Thin wall tubes may
crumple or crease when making close radius
bends. Filling materials such as sand may help
prevent this. Thicker walled tube can cope
with more deformation and therefore can be
bent to a smaller radius

15. • Composition of metal: Pipes may react
differently to being bent and display different
‘spring back’ according to the composition of the
metal.
• Placement of pipe seam: The seam down the
pipe is the weakest part of the tube, and should
not be placed inside or outside of the radius, as
these are the parts of the tube that undergo the
greatest deformation and are prone to crumpling.
•

16. Points to note
• Operate hand bending lever with a firm pull continuously
• Check frequently the angle of bend using a bevel bar or set
wire
• For repetitive bending work, machines are fitted with
degree stop pins or limit switches. When the first bend has
been completed, the degree stop or limit switch is locked in
position. The degree stop or limit switch will stop the
bending lever at the same position on subsequent bends
• When setting the stop pins, make allowance for pipe
‘spring’.
•

17. Hot bending
• Heat may be used to assist bending, usually
with solid materials such as rod or flat band,
which will not deform easily. The heat source
is usually from a welding flame.
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