Description

This Standard specifies requirements for the mass, quality, and testing of hot-dip galvanized coating on steel bolts, screws, nuts and other fasteners having ISO metric coarse threads, in the nominal size range M8 to M36 inclusive. Guidance is also given for oversize tapping allowances for fasteners, with metric coarse threads up to and including M64 diameter.

Scope

This Standard deals with the purity of the galvanizing bath, the appearance of the coating under visual examination, the mass of the coating, the adhesion of the coating, and the test methods to be adopted. It also deals with the oversize tapped screw thread limits for internal threads, but does not deal with other dimensions, depending for these on reference to relevant specifications. After galvanizing, fasteners must comply with the physical property requirements of their relevant specifications when tested in accordance with requirements specified therein.

NOTES:

1. The term 'relevant specification' refers to a specification covering the dimensions and physical properties of metric fasteners as required by the purchaser. This may be an Australian Standard (e.g. AS 1110, 1111, 1112) or any other specification cited by the purchaser.
2. ISO metric coarse threads below M8 and all ISO metric fine pitch threads, generally cannot be successfully hot-dip galvanized without difficulty with regard to the assembly of bolt and nut.
3. This Standard does not specify a requirement for uniformity of coating. Guidance is given in Appendix D.