A must have reference and data chart book for your workshop. The 28 pages contain data on standardised drill sizes and decimal equivalents, details of all popular threads, tapping and clearance drills, UNF, UNC, BSF, BSW, Metric coarse and fine, hardness comparison tables, jig boring co-ordinates for equally spaced holes, allowances for sheet metal bending and Morse tapers. It also contains tables for sine, cosine, tangents and cotangents. The Zeus Chart fits inside a shirt pocket and with its laminated pages will not pick up dirt, grease or oil.