Skip to main content Skip to search Skip to primary navigation Skip to secondary navigation

Performance of high-strength structural bolts in practice

Print
Share

Print
Share

HERA advises that there have been up to 10 reported instances since 1983 where the bolt method called for full tensioning but the bolts were installed snug tight. This leads to problems with bolt failure or the nut loosening some time after installation. A greater number of problems have been encountered where the bolt supplied is not the bolt specified, or where there has been insufficient thread engagement by the nut. NZS 3404 Clause 14.3.6.1.2 specifies that at least one clear thread must protrude above the nut after tightening. Almost all the latter type of problem are construction errors related to holddown bolts being set too low.

Top

This information is published by the Ministry of Business, Innovation and Employment’s Chief Executive. It is a general guide only and, if used, does not relieve any person of the obligation to consider any matter to which the information relates according to the circumstances of the particular case. Expert advice may be required in specific circumstances. Where this information relates to assisting people:

with compliance with the Building Act, it is published under section 175 of the Building Act
with a Weathertight Services claim, it is published under section 12 of the Weathertight Homes Resolution Services Act 2006.

Print

Print this page (recommended)

Print entire guidance document