General Marking out
Marking out or layout means the process of transferring a design or pattern to a anything, as the first step in the
manufacturing/building process.
Garment marking out(inch/m/cm) Road marking out(m/cm) Foundation marking out(m/cm)
Mechanical/Mechatronics Engineering marking out (mostly used measuring units are mm)
Marking out is the scratching of lines on the surface of a workpiece, known as scribing, and is usually carried out only on a single
workpiece or a small number of workpieces.
Marking out process
The two main purposes of marking out are:
➢ to indicate the workpiece outline or the position of holes, slots, etc. If the excess material will have to be removed, a guide is
given for the extent to which hacksawing or filing can be carried out;
➢ to provide a guide to setting up the workpiece on a machine. The workpiece is set up relative to the marking out and is then
machined.
Datum/Reference side/point
The function of a datum is to establish a reference position from which all dimensions are taken and hence all measurements are
made.
Types of Datum
The datum may be a point, an edge, or a center line, depending on the shape of the workpiece.
For any plane surface, two datums are required to position a point and these are usually at right angles to each other.
Point and Edge datums
Marking out equipment
Description Uses Care & Maintenance
1. Steel rule They are for Do not use it welding area.
measuring distances Clean after use
and ruling straight Prevent in contact with
lines. These are made abrasive surfaces.
from hardened and Do not bend it especially
tempered stainless thicker one.
steel, photo-etched for Do not use as a hitting tool.
extreme accuracy and
have a non-glare satin
chrome finish.
2. Scriber The scribers are used Scriber should be brushed
for scribing lines on a clean of any dirt and grit.
metal surface. They Scribers with a metal body
are made from should be stored in a dry place,
hardened and or, if this is not possible, they
tempered steel, should be sprayed with WD40
ground to a fine point and wrapped in an oily cloth to
which should always prevent them from rusting.
be kept sharp to give
well-defined lines.
3. Dividers Dividers are used to Evening the legs of dividers.
scribe circles or arcs Sharpening divider
and to mark off a needlepoints. Since the same
series of lengths such center is often used for both
as hole centers. They the compasses and dividers, it
are of spring bow is best that needles on both be
construction, each of the same size.
the two-pointed steel
legs being hardened
and ground to a fine
point.
4. Engineering marking blue spray It is used to stain or Do not expose it to prolonged
paint a metal object sunlight or extreme heat.
with a very thin layer of
dye that can be Do not puncture the container.
scratched off using a Keep it upright.
scribe or other sharp
instrument to reveal a
bright, yet very narrow
line on the metal. On
surfaces of metal other
than bright metals,
scribed lines may not
be clearly visible. In
such cases the surface
can be brushed or
sprayed with a quick
drying colored dye
before marking out.
This provides a good
contrast, making the
scribed lines easy to
see.
5. Soapstone pencil/chalk Soapstone Do not drop as it breaks easily
pencil/chalk (also
known as Welder's
Chalk and Soapstone)
is mainly used for
marking metal with a
clear, wax-like mark.
6. Engineering squares Squares are for They should be kept dry to
marking straight lines prevent them from rusting.
and checking the After use, dry off any moisture
relative squareness of or liquid such as marking ink
the sides. Both the from your engineer's square
stock and blade are with a soft cloth.
made of steel to Keep away from splatters of
ensure that the tool welding.
remains accurate over
time as well as having
added durability in a
working environment.
7. Punches Center/prick punches Store punches in a dry place
are used to provide a not subject to lot of humidity to
center location for prevent them from rusting.
dividers and trammels
when scribing circles Store punches neatly arranged
or arcs, or to show in a box and not in a bag where
permanently the throw all your punches
position of a scribed together.
line by a row of center
dots. The center dot is
also used as a start for
small diameter drills.
Punches are made
from high carbon steel,
hardened, and
tempered with the
point ground.
They are used for Ensure that the head of the
8. Ball peen Hammers surface hardening by hammer is always firmly
9. impact. They are used attached to the handle.
for striking punches Replace loose, cracked, or
and chisels. The splintered handles. Keep the
peening face is used work area clear of debris.
for rounding off edges Discard any hammer with
of metal pins and mushroomed or chipped face
fasteners, such as or with cracks in the claw or
rivets. Ball-peen eye sections.
hammer heads are
made of heat treated
forged high-carbon
steel or alloy steel.
10. Surface plate Surface plates are Do not litter on surface plates
smaller reference Do not leave objects
surfaces and are unnecessary
placed on a bench to Prevent corrosion and edges
provide a flat surface being nicked.
for smaller workpieces. Clean after use.
Surface plates are Cover felt-lined wood cover
made from cast iron Keep it oiled
machined to various
grades of accuracy.
11. Angle plate Angle plates are used Angle Plate should be cleaned
to hold workpieces before and after its use.
square to the table Apply oil after using the angle
during marking out plate.
operations. They are
made from high cast
iron.
12. Vernier Height Gauge Where a greater Apply oil to the slide way of the
accuracy and speed main beam.
are required, height Zero-point checking: Make sure
gauge in conjunction that the height gauge reads
with angle plate on zero when the scriber
surface plate can be measuring face touches the
used. The vernier surface plate while under the
scale carries a jaw normal light measuring force.
upon which various
attachments can be
clamped. When
marking out, a chisel
pointed scribing blade
is fitted.
13. Files They are used for Files should be stored so that
removal of material, their faces cannot rub against
smoothing, or forming each other, or against other
shapes. Files are tools.
made from tool of Files can be kept in sets with a
hardened steel in the carrying case which provides a
form of a bar or rod storage solution and protection
with many small to files.
cutting edges raised File holders can be built as a
on its longitudinal way of storing.
surfaces.
14. Hacksaw A hacksaw is for Use full length when cutting.
cutting through Ensure that teeth are facing
materials such as away from the handle.
plastic, steel, and Tighten them sufficiently before
other metals. They are use.
made of bimetal such Clean after use.
as carbon steel, high
speed steel and spring
steel.
15. Taps and wrench Taps used to form Clean them after use with
internal threads in the brush.
drilled holes. Keep them separate to
Wrench is for providing minimize rubbing on each
the torque needed to other.
turn the tap back and Do not hit or drop, they are
forth. brittle.
Taps are mostly made Push them back and forth
of High Speed Steel when using them to avoid
(HSS) for softer breaking.
materials and Cobalt Keep slightly oiled.
for hard materials like
stainless steel.
Wrenches are made of
cast iron.
16. Stock and die Dies are mostly made Clean them after use with
of High-Speed Steel brush.
(HSS) for softer Keep slightly oiled.
materials and Cobalt Do not hit or drop, they are
for hard materials like brittle.
stainless steel. Stocks
are made of cast iron
17. Radius gauge Radius gauges are Do not bend or scratch.
used to gauging the Keep them slightly oiled.
acceptance or Do not disassemble the pieces.
rejection of the existing
radii as part of pattern
making, precision
machining, layout
creation and part
inspection. They are
made of thin stainless
steel.
18. Bench vice Bench vise are for Do not leave it tightly closed
holding the object in after use.
position while the work Clean it after use.
is in progress. They Keep it oiled.
made of cast steel or Do not hit on the jaws when
malleable cast iron working.
and some even low Ensure that all the bolts are
carbon steel. always fixed.
19. Cutting paste/fluid It is used for cooling Do not mix/spoil it.
and lubricating Do not punch to make more or
machining region as wider openings.
well as to flush away Keep away from hot surfaces.
the chips produced. It
also improves
machined surface
finish and reduces
cutting tool wear.
20. Drill bits To provide hole Do not leave on the machine.
through drilling action. Clean and put them on the
rack.
Do not use without a coolant or
cutting fluid.
21. Pedestal drilling machine It is used to provide Machine vice should be always
variable speeds and attached be secure.
torque for drilling Clean the machine after use.
purposes. Ensure that the table is tighten
before use.
Keep the table oiled if the
machine left for long periods.
22. File brush For cleaning of files. Do not bend the brush teeth
Do not put heavy tools on top
of it as it will bend the teeth.
23. Soft face hammer A soft-faced hammer Ensure that the head joint is
is designed to offer not cracked.
driving force without Replace damaged faces.
damaging surfaces.
They also reduce the
force transmitted back
to the arm or hand of
the user, by
temporarily deforming
more than a metal
hammer would.
