4.

HAND TOOLS

4.1 INTRODUCTION

In most cases hand-tools are used to perform various tasks in the various processes
to produce a product. These processes involve marking out, cutting, metal removal,
forming and joining. Some tools are used for a particular process only while others
can be used for various processes. We also maintain pumps and some hydraulic
systems and align electric motors, gearboxes, as well as certain conveyer belt
systems. We usually use hand tools for these tasks because it is expensive to set
up machines for very delicate work and repair or maintenance work.

4.2 FILES

A file is a long flat cutting tool which has a surface covered with sharp tooth-like
edges. We use files to smooth edges, remove burrs, small amounts of metals and
shape metal objects to a particular, or finished, size or shape.
File handles are made from wood or
plastic and are available in different
sizes to suit different types and
sizes of files. The handle should fit
tightly onto the tang of the file and
should not be removed for use on
another file. Once a handle has been fitted, it should remain there for the lifespan of
the file.

We use different files to do different kinds of filing and finishing so we organise files
into different classes and grades. We organise files according to the cut, the grade
of the files, what the file looks like in cross section and the length of the file.

Grades of files

We say that a file, which has only a few teeth per centimetre, is rough or coarse,
and a file, which has many teeth per centimetre, is smooth. So the coarseness of a
file depends on the number of teeth per centimetre. We use the term grade to
describe how coarse a file is, that is its degree of coarseness.

We will discuss three different grades of files and where we use them in Table 3.1
Grade Use

Bastard file We file iron casting and do general

roughing out work to quickly remove a
lot of material with the bastard grade.

Second-cut file We use a second-cut grade to rough out

hard metals and to file the work piece
to almost the size it must be.

Smooth-cut file We do the last filing on a work piece to

finish it off to size and to give it a good
 P a g e | 16

finish with a smooth-cut grade. We also

draw file (finishing off) with this grade.

When we draw a file, we use a smooth-cut file and only pull the file in one direction
along the length of the work-piece.

Shapes of files
The most important way of organising files is according to their shape. When we look
at the shape of a file, we consider its shape over the length and the thickness of the
tool. So we discuss the width and the thickness of a file as separate parts of the shape
of a tool.

Type of file Shape Type of cut Uses

Hand files have a Both flat We use them for

uniform width along surfaces are general filing
the length of the double-cut. One purposes, for
thickness narrows side is single-cut example for filing
slightly towards the tip. and the other flat surfaces. We
smooth use the safe edge
to file against
finished surface,
so that we don
not damage the
finished surface.

Flat files have a The flat surfaces We use flat files

uniform thickness and are double-cut for general filing
width for two thirds of and the sides work.
the length. Both the are single-cut.
width and thickness
tapers for the last third
of the length of
the file.

The cross section of the The flat surfaces We file

file is square and the and the sides rectangular holes,
shape tapers for the are double-cut. slots and keyways
last third of the length with square files.
towards the tip.
 P a g e | 17

The cross section of Second-cut and We enlarge round

this file is circular and smooth round holes and circular
taper for the last third files are single- openings and we
of the length towards cut and bastard file rounded, or
the tip. round files are concave, surfaces
double-cut. with this file. We
can also use it to
make slots longer
and to finish off
small, internal,
round corners.

Half-round files have The flat surface We can use the

one flat side and one is double-cut and half-round file to
curved side. The file the curved file flat and
tapers for the last third surface is single- concave surfaces
of its length towards cut. as well as large,
the tip. internal, round
corners.

The cross section of All the sides are This file is used to
triangular files is a 60° double-cut. file internal
triangle and again the corners which
shape tapers for the have angles which
last third of the length are bigger than
towards the tip. 60° and also to
sharpen the teeth
of wood saws.

Using a file
Every time we move a file across the surface of the work piece (we call these
cutting strokes), each tooth removes a small piece of metal. So you need to have a lot
of patience and skill when you do precision filing. You can finish off the work piece to
a precise size by applying the file, using both hands, to the metal with a reciprocating
motion. The mere removal of metal with the aid of a file requires very little skill.
Precision filing requires a high degree of skill and patience, which you can only
acquire after much practice and experience. To master the use of a file is a skill well
worth acquiring.

Caring for files

 The most important part of a file is its teeth. Many of the points we will discuss
are to prevent you from damaging the teeth of the file and the other parts
which are also important. If you care properly for you file, it will have a long
working life. These guidelines explain how to care for you files:
 If you use a new file on hard, rough surfaces too soon, you will break the sharp
edges of the teeth. So first use a new file on soft metals like brass or bronze
 P a g e | 18

and if you work on mild steel, only apply light pressure on the new file. Only
after using the file in this way on soft metals you can use it on hard metals,
rough surfaces of castings or welds.
 Never throw or drop files onto one another because this will chip the teeth of
the file.
 Store files on a vertical rack or in a drawer with partitions between the files. Do
not store files between other tools.
 Use a file brush regularly to remove filings from the teeth and on not simply
knock the file on its edge. If you do not regularly remove the filings, the file can
scratch the work piece and will not remove enough material when you use it.
 Do not strike a file with another tool or use the file to strike something.
 Flies are made from hardened cast steel and break easily if you drop them onto
hard surfaces such as concrete.
 The tang is left soft, that is it is not hardened, and you must not use it as a
lever to open lids or to lift heavy objects.
 Always clean the file when you have finished using it and then put it away.
 Do not use a file if it does not have a handle, or if the handle is broken, badly
fitted or loose. The tang is very sharp and can cause damage.

4.3 HACKSAWS

Like hammers, we can use hacksaws for many different purposes. If you look
at the diagram of a typical hacksaw in figure 3.10, you see that it has the
following parts:
 The adjustable frame can be adjusted to different cutting angles, which lie at
angles of 90° to each other. This also makes it possible for us to fit different
blade lengths.
 The handle is usually made from plastic or a lightweight metal such as
aluminium.
 We adjust the length of the frame with the adjusting screw.
 We use the blade to do the actual cutting work. The blade usually has teeth,
which are hardened and tempered. Different blades are used to cut different
types of materials.
 There are two square pins on either side of the blade to hold the blade in
place between the angle and the frame. These square pins allow the blade to fit
in any of four positions.
 We use the tensioning wing nut, which fastens the blade to the frame to
adjust the tension of the blade.

Types of blades
 P a g e | 19

The general shape of a hacksaw does not change, but we often have to change the
type of blade we use so that we can cut a specific material properly. Hacksaw blades
vary in length and in the size of their teeth, which we call the pitch of the teeth. This
pitch is specified in millimetres (mm) and because the millimetre is a decimal unit of
measurement, we call the tooth pitches metric pitches. Common pitches which we
use are the 1,8 mm, 1,4 mm, 1,0 mm and 0,8 mm pitches.
We can cut almost any material with a hacksaw except for hardened steel.

The Table below give guidelines on how you can select blade for a specific purpose:

Type of material Shape of Blade pitch in mm

section

Soft to mild (medium) Large 1,8 mm: We use a coarse pitch

on soft material so that there is
enough space around the blade
(chip clearance) to clear the
cutting chips. This way we can
then cut faster. 14 tpi

Hard Large 1,4 mm: the finer pitch spreads

the cutting load or pressure over
more teeth and still leaves
enough space for chip clearance.
18 tpi

Hard and soft Pipes, tubing, 1,0 mm: This very fine pitch
conduit keeps tow or more teeth in
contact with the narrowest part
of the work.
24 tpi

Hard and soft Unusual or thin 0,8 mm: this very fine pitch
keeps two or more teeth in
contact with thin materials. 32
tpi

Teeth patterns
The teeth of hacksaw blades are arranged, or set, in a particular pattern so that
the cut, which the blade makes, is wider than the thickness of the blade. This
pattern makes a clearance, or space, between the teeth of the blade and the
cut in the work piece. This clearance stops the blade from sticking in the cut.
You can see two types of pattern, which we find, on the hacksaw blade in
Figures 3.11 (a) and (b). Figure 3.11 (a) shows a staggered tooth set for
blades with a coarse pitch where the teeth tilt out slightly on either side. We
call the pattern shown in figure 3.11 (b) a wave set and we find this pattern on
blades with a fine pitch.
 P a g e | 20

Changing the tension of blade

The following steps explain how to change the tension of the blade:
 After you have chosen a blade, hook it onto the square pins ate the end of
the frame. Make sure that the teeth point away from the handle.
 Tighten the tensioning wing nut to take away any looseness in the blade, in
other words, to take up the slack.
 Turn the tensioning wing nut through two more complete turns. This will
tension the blade.
 After you have made a few cuts with the blade, tighten the blade again
slightly.
 Do not tension the blade too much. This kind of over-tensioning can bend
the frame, or it can break the square springs.

Caring for hacksaws

Take note of the following pints when you care for a hacksaw:
 When you finish using the hacksaw, wipe it clean.
 Before you put the hacksaw away, loosen the tensioning wing nut to release
the tension in the blade. If you leave the blade tensioned, the frame can
bend.
 Do not store the hacksaw in the toolbox with other tools on top of it. This
can damage the hardened teeth of the blade and then the blade will cut
ineffectively or stick in the cutting groove and break off.

4.4 PUNCHES

We use punches to do a wide range of work such as marking-off, driving and

cutting. Punches are made from cast steel or tool steel and are hardened and
tempered.

There are several different types of punches. We will now discuss the different
types of punches and their uses.

Types of punches

We organise punches, like other tools, according to their function and their
shape. Some of the common punches are the centre punch, the dotting punch,
the pin punch and the hollow, or ball, punch.

(a) Centre punches

We use centre punches to mark off holes, which must be drilled. The punch
mark will guide the drill so that when we begin drilling, the drill is in the correct
 P a g e | 21

position. If you look closely at the diagram in figure 3.12 (a), you can see at the
point is ground to an angle of 90°.

(b) Dotting punches

We use the dotting punch in Figure 3.12 (b) to do the following:
 To lightly mark intersecting layout lines when we do sheet metal work.
 To mark the centre of a hole.
 To provide a small mark for divider points when laying out circles or spacing
dimension. The point is ground to a 60° included angle.

(c) Pin punches

Figure 3.13 (a) show an example of a pin punch. We use pin punches to drive
out straight pins, taper pins, cotter pins, and keys, bolts and rivets that are cut
or sheared.

(d) Hollow punches

Figure 3.13 (b) shows a hollow punch, which we also call a bell punch. We use
the hollow punch for cutting holes for bolts or studs to pass through in sealing
gaskets made from cork, leather, rubber or composition materials.

Caring for punches

To take care for a punch, you need to follow these guidelines:

 If you do not use a punch properly, you can damage the punch and the work
piece.
 Keep the centre punch sharp at all times.
 Keep the dotting punch sharp at all times.
 Do not use the pin punch on hard material because the edges will chip.
Keep the point ground flat.
 When you store the hollow punch, make sure that the cutting edge is
protected. When you use the hollow punch, make sure that you place you
work piece on hardwood, plastic or lead to prevent damage to the cutting
edge.

4.5 SCREWDRIVERS

All screwdrivers have the same purpose, which is to drive in or remove

screws. A screwdriver is a tool with a specially shaped end, which we place in
the head of a screw to turn it. Typical screwdrivers have the following parts:
 P a g e | 22

 We hold the screwdriver with the handle, which is one end of the tool.
 The body or shank is made from steel and it stretches from the handle to
the blade.
 The blade is on the opposite end of the shank.
 One type of screwdriver, the flat screwdriver, has a flat blade. The range of
flat screwdrivers is large because there are many different combinations of
the blade size and shank length.
 The other type of blade has grooves and a blunt tip. These are Phillips or
star screwdrivers. The range of Phillips screwdrivers is also large.

Caring for screwdrivers

Take note of the following points when caring for screwdrivers:

 You should always use the correct screwdriver type and size or a particular
screw. If you do not do this, the screw, the screwdriver or both can be
damaged. The screw might not tighten properly or loosen easily.
 Keep screwdrivers clean from grease, grime and rust.
 Keep the blades of flat screwdrivers in their proper shape and regrind
them if they are damaged. Do not regrind Phillips screwdrivers unless
special equipment is available.

4.6 PLIERS

We use pliers to grip, cut, bend and form small pieces of sheet metal or wire
and also to hold fasteners. There are many different types and sizes of pliers
but we will only discuss general purpose, or side cutting, long nose, pipe and
circlip pliers here.

(a) General purpose pliers

The other name for general-
purpose pliers is side-cutting
pliers and these have side
cutters to cut wire with. We
use general-purpose pliers to
grip small cylindrical or flat
sheet metal work pieces. We
also use them to bend wire and thin sheet metal.
Look at Figure 3.15, which show an example of general-purpose pliers.

(b) Long nose pliers

Long nose pliers are generally used
for reaching into tight corners
during mechanical assembly, to
form wire loops and for the
removal of split pins.

(c) Circlip pliers

Circlips are used to locate parts in
position and to restrain longitudinal movement. To fit circlips special pliers
must be used, which are available to fit either internal or external circlips.
Internal pliers compress the circlip while the external pliers expand the circlip
as shown in Figures 3.18 (a) and (b).
 P a g e | 23

Removing an internal circlip

By using circlip pliers the sometimes-
tricky job of removing circlips is made
easy. You must follow these steps to
remove an internal circlip;
 Insert the prongs of the circlip pliers
into the circlip holes.
 Apply pressure to the handles of the
pliers to compress the circlip.
 Once the circlip is clear of its
groove withdraw it carefully.

Fitting an external circlip

The fitting of an external circlip is
generally easier than is the case with
an internal circlip because there is
usually more space in which to work.
Circlip pliers with bent or offset
prongs are also available for use in
confined spaces.

Follow these steps to fit an external circlip:

 Fit the circlip onto the prongs of the circlip pliers and expand the circlip just
enough to pass over the shaft.
 Hold the circlip square so as to avoid damaging the shaft and push the
circlip into position over the shaft in line with the circlip groove.
 Align the circlip with the groove in the haft and release the pressure on the
pliers so that the circlip locates in the groove.

Caring for pliers

Use pliers for their intended purpose only. Keep them clean and occasionally
place a drop of light oil on the pivot point and open and close the handle
several times to work the oil in. This will ensure that the handles open and
close easily.

4.7 SPANNERS
Spanners are used in assembly work to loosen or tighten nuts and bolts. Always
use the correct spanner in any application i.e. correct type, size and length.
Make sure that the spanners fit the nut properly. This is important.
 P a g e | 24

Types of spanners

There are different types of spanners that you will use as a fitter. They are all
different and have different applications. Let us now look at each of these
different types of spanners in more detail.
(a) Adjustable spanners
Various sizes of adjustable or shifting spanners or shifters, as they are also
called, are available. A spanner that you often see is the adjustable spanners
shown in Figure 3.21. A particular spanner can be adjusted to fit a number of
nuts or bolt sizes within its range. You must ensure that you adjust the jaws
tightly against the flats of
the nut to prevent them
from slipping, causing the
nut corners to be rounded.
When using the adjustable
spanner, make sure to pull
against the fixed jaw. This
will prevent the jaws from
springing apart and the spanner will also be less likely to slip. Do not use
the adjustable spanner to apply torque to a bolt or nut, rather use a
torque wrench.

(b) Ring spanner

The ring spanner is so called
because it is completely around
the bolt or nut being turned the
ring contains a series of grooves or
points which engage with all the
corners of the bolt or nut. A ring
spanner can be used in confined
places where a flat spanner cannot be used to turn a nut.
The ring spanner must however be fitted on the nut from the top, and if top
space is not available it cannot be used. Ring spanners can be either straight
or offset to be able to reach down onto the nut where the nut is below the
material surface. This offset-type ring spanner is shown in Figure 3.23 and is
called a goose-neck ring spanner.

(c) Flat spanner

The open-ended flat spanner is used in applications where a ring spanner
cannot fit over the head of the bolt or
nut. The ends of these spanners are
offset at 15° to permit complete
rotation of bolts and nuts in areas
where space is limited by alternately
flipping the spanner over. The two
ends are usually made in different
sizes.

(d) Socket wrench and ratchet handle

The socket wrench set with its accessories is probably the most versatile of
all spanners. Socket wrenches are safer and easier to use and will finish the
work quicker than other spanners.
 P a g e | 25

Sockets have two openings: a square opening into which a ratchet handle fits
and a notched circular opening to fit over and grip the bolt head or nut.
The ratchet shift lever handle, when snapped in one direction pulled, will
result in a tightening action. Then by pushing, it will return to its starting
position without the need
for removing the socket
from the nut or bolt head.
When the shift lever is
snapped in the opposite
direction, pushing the
handle will loosen the nut
and by pulling it will
return to its starting
position.

Extension pieces are available in different lengths, and are used to reach deep
down a hole or recess where other spanners cannot be used, making the socket
wrench even more versatile.

(e) Allen keys

Many fasteners have an internal
hexagon-shaped socket to accept a
wrench or key, which is commonly
known as an “Allen key”. A key of the
correct size must always be used to
prevent rounding the corners of the key.

Greatest leverage is obtained by

inserting the short arm of the key into
the head of the fastener. The long arm
of the key can be used to reach into
deep places.

(f) Chain tongs

Chain tongs are mainly used for gripping and turning pipes of diameters of
between about 100mm and 200mm. The principle of operation will be obvious
to you by observing the
direction of the handle shown
by the arrow in Figure 3.22.
To use chain togs, place the
serrated gripper against the
pipe, wrap the chain tightly
around the pipe and lock the
chain in the slot behind the
serrated gripper.

(g) Stillson wrench

 P a g e | 26

To turn around work piece such as a pipe, a Stillson wrench is used. It has two
hardened jaws with deep serrated teeth. The outer jaw, which is adjusted by a
knurled or serrated nut, is called the hook jaw. It is made with a small amount
of play to provide an automatic and increasingly tighter grip on the round work
piece when the wrench is turned in the direction of the movable jaw. The heel
jaw (which is the non-adjustable jaw) is spring-loaded to give it full floating
action to increase the wrench grip.

The teeth on the jaws are slightly slanted to be able

to grip the pipe effectively.

Caring for spanners

Spanners should only be used for their specific purpose. Take not of the following
points:

 Leverage must not be increased mechanically by using a pipe or other

means. This will put excessive and unnecessary strain on the spanner and
may cause the jaws to spring open or even break.
 The spanners described should never be struck with a hammer. This will cause
burrs and mushrooming which may later cause injuries.
 Always remove burrs and mushrooming which may later cause injuries when
slipping from you hand.
 After completion of the work clean and store them properly.