Measuring and Marking out tool (Metalwork Handtools)

Metal Work Hand tools

Marking out Tools and their uses.

LEARNING
OBJECTGIVE

At the end of this lesson, Student
should be able to:

Define metalwork hand tools

Identify different types of handwork
work tools

Give a simple explanation of the
uses of different types of metalwork
hand tools.

What can
you say
about this

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What is Metalwork?

Metalwork is the making or fabricating of objects out of metals
using processes such as sawing, hammering, chiseling, welding
and so forth.

Marking out tools

Marking out is the process of locating points and drawing required
lines on metals. The principal tools used for these are surface
plate, surface table, scriber, odd-leg calipers, dividers, centre
or dot punches, and try square.

Marking out
tools

Marking out is the process of locating points and lines required
on metals. Tools used for these are

surface plate,

surface table,

scriber,

odd-leg calipers,

dividers,

dot punches,

try square.

Surface table and surface
plate

Both of them are made of cast iron and their
top surfaces are truly flat. Both have legs or
stand for support.

scriber

This is a slender, hardened and tempered
tool steel rod having a sharp point at one or
both ends. It is used for marking lines on
metals. The stem is knurled so as to improve
gripping by hand.

Odd-leg Calipers

It has two legs, one leg has a pointed tip and
the other has a curved tip designed to
engage an edge when in use. It is used for
locating the centre of the cross-section of
bars and discs, marking centre lines, as well
as scribing lines parallel to an edge.

Dot punches

It has a sharper angled tip to produce a narrower and
deeper point. It is also used for marking the centre of a
hole to be drilled and Emphasizing a line on sheet
metal.

Try square

It is used for marking and measuring material in
metalworking. It has two parts: a blade and a stock.
The blade and stock are fixed together at 90° to
form an "L" shape.

METAL WORK HAND TOOLS:

MEASURING TOOLS

AND THEIR USES

Measuring tools

These are tools used to measure distance on a metal
plate, bar or rod. Metal tools used for these are:

Steel or Engineer rule.

Inside Caliper

Outside Caliper

Protractor

Centre square

Micrometer screw gauge

Vernier calipers

Steel or Engineer rule.

It is used for measuring lengths. It is made from
carbon steel or stainless steel. They are made in
various lengths.

Inside and outside
Caliper

They have a pair of curved legs. The legs of inside
calipers curve outward while those of outside calipers
curved inwards. Inside calipers are used to obtain the
inside widths of pipes and rings. Outside calipers are
used for obtaining outside widths of shapes such as
balls, and round bars. Once the required width is
obtained, the tips of the callipers are placed against a
steel rule and the measurement is read.

Protractor

This is a semicircular or circular instrument
graduated in degrees at its edge. It is used for
measuring and marking off angles.

Centre square

A centre square is used for finding the
centre of the cross-section of a round bar
as well as checking angles of 45 and 90.

Micrometer
screw gauge

It is used for measuring small thicknesses (e.g diameter
of a wire) to a high degree of accuracy. Its main parts are
ratchet stop, thimble, sleeve, locking nut, spindle,
frame and anvil.

CLASS ACTIVITIES

What is Metalwork?

What are marking out tools?

List some of the instruments
used for marking out in
metalwork.