AS/NZS 1559:1997

Specifies dimensional material and marking requirements for single nut and double nut hot-dip galvanized steel bolts with associated nuts and washers for tower construction with ISO metric coarse pitch series threads in diameters from 12mm to 30mm inclusive and lengths up to 160mm for single nut bolts, 125mm for double nut bolts and from 180mm to 270mm for step bolts. Clamping lengths are tabulated in an appendix and equations for the determination of the clamping lengths are given.

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.

Originated in Australia as AS 1559-1986.
Jointly revised and designated AS/NZS 1559:1997.