Hot dip galvanized (HDG) bolts, nuts and washers are widely accepted as the most economical, reliable, and easy to use structural fasteners. They are used to connect galvanized, painted, and uncoated structural steel and other steel products.

This best practice guide includes information on the characteristics, advantages, and economics of bolted structures and hot dip galvanized fasteners, as well as offering comment on bolting procedures when these are influenced by the presence of zinc coatings. Information provided is in accordance with current Australian and International Standards, and with the rationalised approach to the design, detailing and fabrication of structural connections developed by the Australian Steel Institute. 

The information in this guide has been developed from work previously published by the Galvanizers Association of Australia, along with more recent publications by the Australian Steel Institute and the International Zinc Association. This edition of the guide also includes the results of the latest international research on slip factors for hot dip galvanized connections. 

Figure 1: Roadside barriers come in all sizes and shapes, with this HDG crash barrier and sculpture bolted directly onto the concrete wall on this overpass in Queensland