training module is designed to give you a good appreciation on the various
types of band tools commonly used for measurement, marking out, and metal
removal. Emphasis is not placed on you to become a skilful fitter within
such a short period of training, but rather to let you understand the
uses of common hand tools and appreciate the importance of fitting work
in the trade. Nevertheless, on completion of the training and through
the hands-on practice given, you will acquire some of the basic skills
and techniques involved with these hand processes.
the maximum benefit from the training, it is essential that you use every
opportunity to consolidate what you observe and to interact between yourself
and the staff member in charge of your training. This is self-motivated
and the drive must come from you.
2. Why Use Hand Tools?
without Tools is nothing; with tools he is all." - This sentence is defined
by Thomas Carlyle has well elaborated the importance of tooling to a man.
'Tooling' as applied to the engineering discipline refers to any
equipment or instruments that give helps in the production of a product
or any related activities. Simply
speaking, it ranges from the most fundamental type of hand tools such
as a File to the very complex machine tools such as a CNC Machining Centre.
one may ask the question - Why we still have to use band tools in this
modern age of technologies?
it is reasonable to say that the efficiency of any hand processes is low
and the outcome quality depends highly upon the skill of individuals.
Perhaps it is fair to consider the following points before a definite
answer is given to the above question: -
Although the CNC
machine can give a higher degree of dimensional accuracy when compared
with the inconsistent outcome of hand fitting, the extreme high degree
of flatness required for a surface table or a machine slideway is usually
obtained by hand scraping only.
Hand processes are
very flexible and can be carried out at any place where necessary while
machining processes are not. In addition, machining usually require
a rigid setting up, while fitting is simple.
For large batch
size, advanced production machines are commonly employed in order to
maintain the accuracy as well as the efficiency. But for "jobbing type"
works, such as the manufacture of a prototype or the repairing of a
single component, it would be uneconomic to use these advanced machine
tools. Instead, "jobbing type" works are usually produced by conventional
machining and followed by hand fitting where necessary.
In the assembly
of precise component parts, no matter how accurate they are being produced,
a skilled fitter is often required to give the necessary "finishing
touch" on them to ensure that everything goes together correctly.
3. Measuring Tools in
the very simple tools used together with a steel rule for the measurement
or comparison of linear dimensions. An experienced worker can achieve
+/-0.05mm in the measurement. Calipers are classified into two types:
Outside calipers (figure 1) are used for measuring external dimensions
such as the length, diameter, or even the thickness of a solid.
Inside calipers (figure 2) are used for measuring internal dimensions
such as the diameter of a hole, or the width of a slot etc.
Calipers (figure 3) are more precise tools capable for measuring
external dimensions, internal dimensions, and depths. Besides the
two pairs of measuring jaws and the depth gauge, its main features
also include a main scale and a vernier scale.
of a vernier scale is determined by the difference on the distance
of one division on the main scale and one division on the vernier
as shown in figure 4. For example: A vernier scale of length 49mm
is divided into 50 equal divisions. That means ONE division
on the vernier represents 49/50=0.98 mm while ONE division on the
main scale represents 1mm. Then, the resolution of the vernier is
1mm - 0.98mm = 0.02mm.
Vernier Height Gauge
vernier height gauge (figure 5) is used for measuring height of
an object or for marking lines onto an object of given distance
from a datum base.
Vernier Height Gauge
is a more precise measuring instrument than the vernier calipers. The
accuracy is come from the fine thread on the screw spindle. The ratchet
prevents excess force from being applied. Generally, the screw spindle
has a pitch of 0.5mm. The thimble is divided into 50 equal divisions.
types of micrometers used in the workshops are: -
outside micrometer (figure 6) is used for measuring external dimensions.
The work to be measured is placed between the anvil and the tip
of the spindle.
is similar in structure to an outside micrometer and is used for
measuring internal dimensions as shown in figure 7.
depth micrometer (figure 8) is used for measuring the depth of a
hole, slot and keyway etc. A complete set of depth micrometer is
equipped with spindles of different lengths, which can be interchanged
to suit different measuring ranges.
protractor (figure 9) is a general purpose tool used for the measuring
/ checking of angles e.g. the angle of drill head, angle of cutting
tool, and even for the marking out of angles on a component part.
This is a precision
measuring tool that the accuracy of measurement can reach ¡Ó5
minutes of an angle through the vernier scale as shown in figure
set (figure 11) is a set of equipment combining the functions of protractor,
engineer square, steel rule, Centre finder, level rule, and scriber.
Figure 11. Combination
The principle of dial indicator (dial gauge) is that the linear
mechanical movement of the stylus is magnified and transferred to
the rotation of pointer as shown in figure 12. The accuracy of dial
indicator can be up to 0.001mm. It is usually used for calibration
4. Marking Out Tools
out is the preliminary work of providing guidance lines and centres before
cutting and machining. The lines are in 3-D and full-scale. The workpiece
can then be cut or machined to the required shapes and sizes. The common
tools used for marking out are as follow:
A scriber (figure
13) is used for scratching lines onto the workpiece. It is made
of hardened tool steel.
(figure 14) is made of hardened tool steel. It is used for checking
the straightness and the squareness of a workpiece. It can also
be used for marking perpendicular lines onto a workpiece.
(figure 15) are made of hardened tool steel. The legs are used for
scribing arcs or circles onto a workpiece.
are two types of punch namely the Centre Punch and the Dot Punch.
A dot punch has a point angle of 60¢X and it is used for making
of small dots on the reference line. The centre punch has a point
angle of 90¢X as shown in figure 16 and it is used for making
a large indent on a workpiece for drilling. Both punches are made
of hardened tool steel.
plate (figure 17) is made of malleable cast iron. It has been machined
and scraped to a high degree of flatness. The flat surface is being
used as a datum surface for marking out and for measuring purposes.
If it can stand on the floor, it is called surface table.
angle plate (figure 18) are used for supporting or setting up work
vertically, and are provided with holes and slots through which
securing bolts can be located. It is made of cast iron and ground
to a high degree of accuracy.
blocks (figure 19) usually in a couple are made of cast iron or
steel in case-hardening. They are generally used for holding circular
workpiece for marking out or machining.
5. Hand Tools for Workshop
bench vice (figure 20) is the device for holding the workpiece where
most hand processes to be carried out. The body of the vice is made
of cast iron while the two clamping jaws are made of hardened tool
steel. Some bench vice has a swivel base, which can set the workpiece
at an angle to the table. The vice height should be correct ergonomically.
Vice clamps, made of copper are fitted over the vice jaws when holding
finished work to avoid damage to the finish surfaces.
- Do not direct
impact the vice body by the hammer.
- Light hammering
can be done on and only on the anvil of the vice.
- To avoid
over clamping, the handle of the vice should be tightened by hand
20. Bench Vice
are the most important hand tools used for the removal of materials. They
are made of hardened high carbon steel with a soft 'tang'. to which a
handle can be fixed. Files
are categorised as follows:-
Figure 21. File
- measured from the shoulder to the tip.
Shape - the
Grade - the
spacing and pitch of the teeth.
Cut - the patterns
of cutting edge.
are no cutting edges on one side of the hand file. The purposes for the
save edge is to avoid the worker damage the work, when he is filing a
shoulder position. Shape of Files
Hand File - The common file used for roughing and finishing.
It is a rectangular in section and parallel in width. It has double
cut teeth on two faces, single cut teeth on one edge, and one save
2. Flat File
- It is similar to a hand file rectangular in section, tapered slightly
in width and thickness towards the tip. It has Double Cut teeth
on two faces and Single Cut teeth on two sides.
File - The section is a chord of a circle with its taper towards
the tip. It is used for forming radii, grooves, etc. and the flat
side is used for finishing flat surfaces.
File - This is of round section tapering toward the end. It
is used for enlarging holes, producing internal round corners. Usually
double cut in the larger sizes, and single cut for the smaller sizes.
Figure 22d. Round File
File - This is square in section, with tapered towards the tip,
and usually double cut on all four faces. It is used for filing
rectangular slots or grooves.
Square File - It is also known as triangular file. This is a
triangular in section, with tapered towards the tip with double
cut on both faces. It is used for filing corners or angles less
Figure 22f. Three Square File
Files - Needle files are a set of small files with their shapes made
in a way similar to the large ones. They are generally used for small
and delicate works such as the repair of small instruments.
refers to the pitch (spacing) of the teeth that spread throughout the
whole length of the file. Files with a rougher grade of cut give a faster
metal removal rate but a poorer surface finish or the vice versa. It should
be noted that, for the same grade of cut, a longer file would have a coarser
pitch than a shorter one.
are as follows:
cut - medium teeth for general purposes, especially suitable for mild
cut - finer teeth for cutting hard metals.
cut - fine teeth for finishing.
grades of cut are in common use
Cut - There is only one set of cutting teeth to one edge. It gives
a less efficient cutting but a better finish. It is suitable for the soft
Cut - A double cut file has one set of teeth cut at 70 degrees to
one edge, and another set of grooves cut at 45 degrees to the other edge.
It is thus more efficient in cutting. It is easy to clog the teeth when
it is work on the soft metal.
- Very coarse teeth, like the nail, it is commonly used for the cutting
off soft materials such as rubber, PVC, or wood etc.
and Care of Files
teeth are brittle and therefore file should be placed properly and should
not be stacked on other tools.. New files should never be used on hard
materials. E.g. castings or welding. Some brittle metal, e.g. brass is
not readily filed with the worn teeth. A new file should be used for these
purposes and the file must be kept in another stock. Remove the pinning
regularly by a file card/wire brush. Cutting is carried on the forward
stroke. It is very danger to use files without handles.
When filing the soft
metals, the small pieces of metal will tend to clog the teeth. If the
file is not cleaned, this small piece of metal will scratch on the surface
of the work. We call it pinning. This case is frequently appeared when
applying a new smooth file on the soft metals. The pinning can be removed
with a File Card as shown in figure 23, which is a wire brush mounted
on a block of wood. Sweep the file card along the grooves on the file
until the pinning is removed.
Figure 23. File
A hacksaw is generally
used for cutting a metal into pieces.
It consists of a
frame and a saw blade as shown below. It is a "U" shaped steel frame with
a pistol handgrip and a saw blade as shown in figure 24. The frame may
be of fixed type to take only one length of blade, or adjustable to take
different blade lengths. It has a wing nut to adjust the tension of the
Figure 24. HackSaw
Saw blades are made
of high carbon steel, alloy steel or High Speed Steel. They are supplied
according to material, hardening, length and pitch.
- Usually the saw blade is supplied with all hard or flexible grade. The
all hard is very brittle, and it is suitable for the skillful user only.
The flexible grade is tough, so it can twist an angle. It is suitable
for cutting a curve or for the beginner to use.
- Usually the saw blade is supplied with High Carbon Steel (HCS) and High
Speed Steel (HSS). The HCS will annealed from the heat generated by fraction
of cutting. The HCS, saw blade will lost its hardness when cutting the
hard metal. The HSS can keep its hardness unless improper use.
- It is grading according to the number of teeth per 25mm.
Coarse blade (18T) is most suitable for soft material and
Medium blade (24T) is suitable for steel pipe.
Fine blade (32T) is suitable for the thin metal sheet and
thin copper pipe.
it is advice that to keep at least 3 teeth of the blade, stand on
Pitches of Saw Blade
- The length of the blade is determined by the distance between the outside
edges of the holes, which fit over the pegs.
- The teeth have a "set" to either side alternately, which causes the
blade to cut a slit wider than the thickness of the blade, to prevent
Safety and Care
- The cutting action
is carried on the forward action only. So the blade must be mounted
with its teeth pointing forward.
Suitable tension should be applied on the blade to avoid breakage or
the blade if some teeth are broken.
Avoid rapid and erratic strokes of cut.
- Avoid too much
- Workpiece must
be hold firmly.
The type most commonly
used is the ball pein hammer, which has a flat striking face and a ball-shaped
end (call the pein). Hammer heads are made from medium carbon steel. The
two ends must be hardened and tempered, the centre of the head with the
eye being left soft. It is specified according to its weight.
Figure 26. Hammer
and Care of Hammer
- The hammer head
is firmly fixed to the shaft by a wedge.
- The striking face
of the hammer head does not wear.
Drill and Drilling
the process of cutting holes in metals by using a drilling machine
as shown in figure 27. Drills are the tools used to cut away fine
shavings of material as the drill advances in a rotational motion
through the material.
The twist drill
(figure 28) is made from High Speed Steel, tempered to give maximum
hardness throughout the parallel cutting portion. Flutes are incorporated
to carry away the chips of metal and the outside surface is relieved
to produce a cutting edge along the leading side of each flute.
Figure 28. Twist Drills
The point of
the drill is ground to an angle of 59¢X to the centre line to
give two equal cutting edges, and each side is ground back to give
" relief " of about 12¢X to each cutting edge as shown in figure
It is very
important that drill points are central and that the lip angles
are equal and that the cutting edges are unchipped and the clearance
angle correct. To obtain this state and ensure correct angles it
is important that drills are ground in a grinding machine.
Drill Operating Parameters
It is essential to
select the correct cutting speed and the feed. Followings are the most
common used cutting speed and feed rate.
6 - 9 m/min
¡V 9 m/min
¡V 36 m/min
| 5.5 mm diameter
¡V 0.15 mm/rev
|30 mm diameter
¡V 0.55 mm/rev
Special Type of Drill
Drill (figure 30) ¡V To form a flat, or cylindrical recess
to accommodate the head of the bolt. It is also used to provide
a level base on the rough surfaces for nuts and washers.
Drill (figure 31) ¡V To form a conical shaped recess to
enable a countersunk screw or bolt to fit flush with the surface
of the work.
Safety and Care on Drilling
- Twist drill
must be clamped in the drill chuck tightly
- The workpiece
to be drilled must be firmly secured by vice, or clamps.
- Drill guard
(figure 32) must be closed before switch on the machine.
- Use the
correct drilling speed and apply suitable drilling force It is
advisable to release the drill occasionally, lift the drill, and
clear the hole of cutting.
- Apply cutting
fluid in the cutting except for drilling Cast iron.
- Take care,
when the drill is nearly penetrated through the workpiece.
- The "screw
in" action can lift up the workpiece.
Reamer and Threading Tools
of reamer are
- to control the
diameter of a hole
- to improve the
internal surface finish
- to improve the
roundness of the hole
is made of hardened High Carbon Steel or High Speed Steel. It is classified
into hand reamer and machine reamer.
reamer (figure 33) has two types of flutes: - straight and spiral
flutes. The spiral flutes hand reamer has a left hand spiral flutes.
The purpose of the design is to prevent the reamer "screw in" the
reamer (figure 34) has a straight shank or taper shank (Morse taper).
The taper shank can fit directly into the spindle of a machine while
the straight shank is hold by the collet.
| 3. Expanding
cutting diameter can be slightly varied by adjusting an inner taper
against the loss cutting blades as shown in figure 35. This type
is used primarily for repetitive work to maintain a consistent size
Safety, Precautions & Operation in Reaming
- Care the sharp
cutting edge especially in handling.
- The amount of material
to be removed by a reamer should be as small as possible, approximately
2-4% of diameter.
- Reamer must only
be turned in one direction, both cutting and removing the tools, otherwise
the tool may jam.
- Lubricant oil
should be used except when cutting cast iron and brass.
- Reaming can enlarge
the size of hole, but cannot correct the position error in drilling.
Taps (figure 36) are
used to cut the internal screw threads. Taps are made of hardened High
Carbon Steel or High Speed Steel. The ends of the shank are square to
fit a wrench (figure 37). Usually taps are provided in set of three --
taper, second and plug tap.
The tap is tapered off for a length of 8 to 10 threads and is the
first tap to be used in a hole to start the thread form.
The tap is tapered off for a length of 4 to 5 threads to facilitate
picking up the threads cut by the taper tap.
This is fully threaded throughout its length and is called a 'bottoming'
tap. This tap used to cut the bottom of a blind hole.
Precautions & operation
- The size of the
hole is important and the correct drill size should be determined from
the handbook, standard table in the workshop or the recommendation on
the shank of the tap.
- Use taper tap first
ensuring that it is kept square with top surface of work
- Always use the
correct size of wrench for the tap in use.
- Lubricant oil
should be used except when cutting cast iron and brass.
- Use both hands
to hold the wrench to maintain even torque.
- About every half
turn reverse action slightly to break the swarf and clear the threads.
- When the tap reaches
the bottom of the blind hole, care must be taken not to force as tap
may break in the hole.
Dies are used for
cutting external threads on round bar or tubes. Dies are made of Hardened
High Carbon Steel or High Speed Steel.
1. Split Die or
is held in place in the stock as shown in figure 38. The split permits
a small amount of adjustment in the size of the die by adjusting the screws
in the stock. Since split dies cut their thread complete in one cut, the
die thread are tapered and back off for one third of their length.
Split Die & Stock
|2. Die nuts
nuts (figure 39) are not capable of any adjustment. They are not usually
employed for cutting threads from the bar, but for rectifying damage
to existing threads. They are externally formed to hexagonal shape
for use with a spanner.
Operation of Die
- The diameter of
the blank rod must not larger than the outside diameter of thread to
- Ensure that the
die is set perpendicular to the rod.
- Lubricant oil should
be used except when cutting cast iron and brass.
- About every half-turn
reverse frequently to break the swarf otherwise the thread will tear.