Marking out requires two straight edges on the material.
The straight edges are at right angles to each other and are used as references.
These references are called datum references.
Checking the Datum References
steel rule -> check the straightness of an edge
try square -> check whether two edges are at right angles to each other on wood or plastics
engineer’s square -> check whether two edges are at right angles to each other on metal or plastics
scriber -> mark lines on a metal workpiece
sharp pencil -> mark lines on a wooden workpiece
spirit-based felt pen -> mark lines on bare plastics
Use an engineer’s square and a scriber to mark a line at right angles to the datum edge of a metal workpiece.
Use a try square with a pencil to mark a line at right angles to the face side or face edge on a wooden workpiece.
A marking knife is used with a try square to cut a line across the grain of a piece of wood where a section of the wood needs to be removed.
Marking Lines Parallel to an edge
odd leg calipers -> mark lines parallel to the datum edge on a metal or plastics workpiece
Odd-leg calipers can also be used to find the centre of a round bar.
marking gauge -> mark lines parallel to the face side or face edge on a wooden workpiece
A marking gauge can be set using a steel rule.
spring dividers -> mark circles or arcs on a metal workpiece
template -> mark out a freeform shape; to mark out more than one shape identically
A template can be made from card or paper. Then cut and paste it directly on the material surface.
ball-pein hammer -> punch marks on metal workpieces by striking a punch
centre punch -> mark the centre of a hole that is to be drilled on a metal workpiece
dot punch -> mark small dots (witness marks) along a scribed line on a metal workpiece
steel rule -> measure lengths on all materials