1 Scope
This standard specifies pattern dimension, technical condition, and marking of high strength large hexagon bolt with thread specification M12-M30.
This standard is applicable to railway and Highway Bridge, boiler steel structure, industrial premises, high floor civilian construction, tower mast structure, hoisting machinery and other steel structure friction-type high strength bolt connection.
2 Normative references
The following normative documents contain provision which, through reference in this text, constitute provisions of this national standard. For dated reference, subsequent amendments to, or revision of, any of these publications do not apply. All standards are subject to revision, and parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. For undated references, the latest edition of the normative document referred to applies.
GB/T 2 Fasteners-Ends of Parts with External Thread (GB/T 2—2001, idt ISO 4753: 1999)
GB/T 1231 Specifications of High Strength Bolts with Large Hexagon Head, Large Hexagon Nuts, Plain Washers for Steel Structures
GB/T 1237 Designation System for Fasteners (GB/T 1237—2000, eqv ISO 8991: 1986)
GB/T 5276 Fasteners; Bolts, Screws, Studs and Nuts; Symbols and Designations of Dimensions (GB/T 5276—1985, eqv ISO 225: 1983)
3 Dimensions
Dimensions see figure 1 and table 1-table 3. Dimension designation and labels are in accordance with those specified in GB/T 5276. Dimensions and labels of thread end are in accordance with those specified in GB/T 2.
