This Standard specifies the requirements for hot-dip galvanized bolts and step bolts with ISO metric coarse pitch series threads for normal and low temperature applications in tower construction, and associated nuts and washers. Bolt sizes are as follows:(a) Single-nut type bolts in diameters from 12 to 30 mm inclusive with lengths from 35 to 160 mm inclusive.(b) Double-nut type bolts in diameters from 12 to 30 mm inclusive with lengths from 50 to 125 mm inclusive.(c) Step bolts 16, 22 and 24 mm in diameter with lengths from 180 to 270 mm inclusive.NOTE: The single-nut and double-nut bolts are known as 'tower bolts' and have a thread length/bolt length relationship to enable threads to be excluded from shear planes when assembled.