Stock Forms, Types And Sizes

A student designs a shelf 650 millimetres long because it looks right. The sheet it will be cut from is 2440 millimetres long, and 2440 divided by 650 is 3.75, so three shelves come out of that length and a quarter of the sheet is thrown away. Had the shelf been 610 millimetres, four would have come out with nothing left over. Forty millimetres of drawing, decided in a second, changed the material cost of the product by a quarter.

This lesson is about the sizes materials actually come in and the components you can actually buy. You will learn the commercially available types and sizes for papers and boards, timber based materials, metal based materials and polymers, what each is sold by, and the standard components that go with them: fasteners, seals and bindings; woodscrews, hinges and knock-down fittings; rivets, machine screws, nuts and bolts. Then you will use them, calculating how many parts come out of a sheet and how to lose less of it. This is specialist technical principles content, examined in Section B of Paper 1, and it is the topic the paper's own maths column leans on hardest.