Measuring and marking-out tools
Copying the shape and sizes from a drawing onto a blank is called marking out. For thin sheet metal we use a centre punch, steel ruler, scale ruler, 90° square and marking compass; a vernier caliper is also used for measuring. The centre punch leaves small dimples along the line so it does not rub off during work, and striking it with a hammer is done only the way the teacher shows. Before marking, recheck the sizes on the drawing, because a wrong measurement spoils all later work. Workshop rules: come on time, wear work clothes, listen carefully and tidy the workplace at the end of the lesson.
Marking on paper: a drawing of a square with 6 cm sides is given. The pupil copies it onto a “blank” (paper) with a ruler, set square and compass and checks the diagonals (they must be equal). Done without metal or sharp tools.