1 Scope
This document specifies the type dimensions, technical conditions and marking of reinforced half-round head square neck bolts.
This document applies to reinforced half-round head square neck bolts with thread sizes M6 to M20 and product grades B (type A) and C (type B) bolts.
2 Normative references
The contents of the following documents constitute the essential provisions of this document through the normative references in the text. Among them, note the date of the reference document, only the date of the corresponding version applies to this document; do not note the date of the reference document, its latest version (including all the revision of the list) applies to this document.
GB/T2 Fasteners male threaded parts ends
GB/T 90.1 Acceptance inspection of fasteners
GB/T 90.2 Fastener marking and packaging
GB/T 193 Common thread diameter and pitch series
GB/T 1237 Fastener marking methods
GB/T 3098.1 Fastener mechanical properties bolts. Screws and studs
GB/T 3098.6 Fasteners mechanical properties of stainless steel bolts, screws and studs
GB/T 3103.1 Fastener tolerances bolts screws, studs and nuts
GB/T 5267.1 Fastener plating
GB/T 5267.2 Fasteners non-electrolytic zinc flake coating
GB/T 5267.3 Fasteners hot dip galvanized layer
GB/T 5276 Fastener bolts, screws, studs and nuts size code and labeling
GB/T 5779.1 Fasteners surface defects bolts, screws and studs general requirements
GB/T 9145 General thread medium precision, the limit size of the preferred series
GB/T 9146 General thread rough accuracy, the limit size of the preferred series
GB/T 16938 General technical conditions for fasteners bolts screws, studs and nuts
3 Terminology and definitions
There are no terms and definitions that need to be defined in this document.
4 Type size
Type A bolt type and size see Figure 1 and Table 1, Type B bolt type and size see Figure 2 and Table 2.
The dimensional designations and labelling should be in accordance with GB/T 5276.
5 Technical conditions and referenced standards
Technical conditions and referenced standards are shown in Table 3.
6 Marking
6.1 Marking method
Marking methods shall be in accordance with GB/T 1237.
6.2 Marking example
Thread size M12 nominal length l = 70 mm, performance level 8.8, the surface is not treated with the markings of the type A reinforced semi-round head square neck bolts:
Bolt GB/T 794 M12X70
Bibliography
Foreword
1 Scope
2 Normative references
3 Terminology and definitions
4 Type size
5 Technical conditions and referenced standards
6 Marking
Bibliography
