An extremely handy pocket sized reference booklet of data charts and tables for the drawing office, toolroom or workshop.This metric revision publication is produced by Zeus Precision Charts Ltd, who are members of the British Standards Institution.The 28 laminated pages contain data on standard drill sizes and decimal equivalents, tapping drills and clearances for metric and imperial threads, BS4500 tolerances, hardness comparisons, jig boring co-ordinates for equally spaced holes, allowances for sheet metal bending and Morse tapers. Also, long tables for sine, cosine, tangents and cotangent.