1 Scope
This Part specifies material, process, dimensional and some performance requirements for hot dip spun galvanized coatings applied to coarse threaded steel fasteners from M8 up to and including M64 and for property classes up to and including 10.9 for bolts, screws and studs and 12 for nuts. It is not recommended to hot dip galvanize threaded fasteners in diameters smaller than M8 and/or with pitches below 1.25 mm.
Note: Attention is drawn to the fact that the proof loads and stresses under proof load of oversize tapped nuts with threads M8 and M10 and the ultimate tensile loads and proof loads of undersize threaded bolts and screws with threads M8 and M10 are reduced as compared to the values specified in GB/T 3098.2 and GB/T 3098.1 respectively and are specified in Appendix A.
This Part primarily concerns the spun hot dip galvanizing of threaded steel fasteners, but it may also be applied to other threaded steel parts.
The specifications given in this Part may also be applied to non-threaded steel parts such as washers.
2 Normative References
The following normative documents contain provisions which, through reference in this text, constitute provisions of this Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies.
GB/T 197 General Purpose Metric Screw Threads — Tolerances (GB/T 197-2003, ISO 965-1:1998, ISO General purpose Metric Screw Threads — Tolerances — Part 1: Principles and Basic Data, MOD)
GB/T 1237 Designation System for Fasteners (GB/T 1237-2000, eqv ISO 8991:1986)
GB/T 2516 General Purpose Metric Screw Threads — Limit Deviations (GB/T 2516-2003, 965-3:1998, ISO General purpose Metric Screw Threads — Tolerances — Part 1: Deviations for Constructional Screw Threads, MOD)
GB/T 3098.1 Mechanical Properties of Fasteners — Bolts, Screws and Studs (GB/T 3098.1-2000, idt ISO 898-1:1999)
GB/T 3098.2 Mechanical Properties of Fasteners — Nuts — Coarse Thread (GB/T 3098.1-2000, idt ISO 898-2:1992)
GB/T 4956 Non-magnetic Coatings on Magnetic Substrates — Measurement of coating Thickness — Magnetic Method (GB/T 4956-2003, ISO 2178:1982, IDT)
GB/T 9145 General Purpose Metric Screw Threads — Limits of Sizes for the Screw Threads of Medium Quality and Preferable Plan (GB/T 9145-2003, ISO 965-2:1998, ISO General purpose Metric Screw Threads — Tolerances — Part 2: Limits of Sizes for General Purpose External and Internal Screw Threads — Medium Quality, MOD)
GB/T 12334 Metallic and Other Inorganic Coatings — Definitions and Conventions Concerning the Measurement of Thickness (GB/T 12334-2001, idt ISO 2064:1996)
GB/T 13825 Metallic Coatings — Hot Dip Galvanized Coatings on Ferrous Materials — Gravimetric Determination of the Mass Per Unit Area (GB/T 13825-2008, ISO 1460:1992, IDT)
GB/T 13912 Metallic Coatings — Hot Dip Galvanized Coatings on Fabricated Iron and Steel Articles — Specifications and Test Methods (GB/T 13912-2002, ISO 1461:1992, Hot Dip Galvanized Coatings on Fabricated Iron and Steel Articles — Specifications and Test Methods, MOD)
GB/T 22028 Hot-dip Galvanized Screw Threads — On internal Screw Threads There Is the Clearance for Accommodating the Hot-dip Galvanized Coat (GB/T 22028-2008, ISO 965-5:1998, ISO General purpose Metric Screw Threads — Tolerances — Part 5: Limits of Sizes for Internal Screw Threads to Mate with Hot-dip Galvanized External Screw Threads with Maximum Size of Tolerance Position h Before Galvanizing, MOD)
GB/T 22029 Hot-dip Galvanized Screw Threads — On internal Screw Threads There Is the Clearance for Accommodating the Hot-dip Galvanized Coat (GB/T 22029-2008, ISO 965-4:1998, ISO General purpose Metric Screw Threads — Tolerances — Part 4: Limits of Sizes for Hot-dip Galvanized External Screw Threads to Mate with Internal Screw Threads Tapped with Tolerance Position H or G After Galvanizing, MOD)
3 Terms and Definitions
