1 Scope
This standard specifies general matters relating to significance of tightening by combination of bolt and nut, basis of tightening and representative control method.
Further, this standard is applicable to bolted joint other than the bolt and nut.
However, it is not applicable to bolted joint with spring washer or elastic washer, or bolted joint where self-tapping screws, wood screws, or prevailing torque type1) threaded fasteners are used.
2 Normative references
The following standards contain provisions which, through reference in this text, constitute provisions of this standard. At the time of publication, all the editions listed are valid. All standards are subject to revision, and all 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.
GB 3098.1-82 Mechanical properties of fasteners - Bolts, screws and studs
GB 3104-82 Fasteners - Widths across flats of hexagon products
GB 5277-85 Fasteners - Clearance holes for bolts and screws
GB 9145-88 General purpose screw threads - Limits of sizes for commercial bolt and nut threads - Medium quality
GB/T 16823.1-1997 Stress area and bearing area for threaded fasteners;
GB/T 16823.3-1997 Method of tightening test for threaded fasteners.
3 Terms and symbols
3.1 Terms
For the purpose of this standard, main terms and their definitions shall be in accordance with Table 1.
Foreword i
1 Scope
2 Normative references
3 Terms and symbols
4 Significance of tightening
5 Base of tightening
6 Tightening control of screw threads
Annex A (Normative) Calculation values of torque coefficient to coefficient of friction between threads and coefficient of friction between bearing surfaces
Annex B (Normative) Calculation values of yield clamping force and yield tightening torque to coefficient of friction between threads and coefficient of friction between bearing surfaces
