1. Scope
The standard specifies the mechanical property of screw bolt, screw nail and bolt made of carbon steel or alloy steel in the test under the environmental temperature 10 ~ 35℃.
The products, which meet requirements of the standard under the environmental temperature, may have different mechanical/physical properties under higher or lower temperature. Appendix A (Suggestive Appendix) provides the demonstrations of yield point (σs) or specified non-proportion elongation stress (σp0.2) under the hot condition.
Product performance, especially impact ductility, may change blow the environmental temperature, so user shall pay more attention to this.
B) some fastener like countersunk head, semi-countersunk head or round column head, which physical dimension of header leads to the shear section of header being less than the stress sectional area of screw thread, may not meet the tensile or torsional requirements in this standard (Chapter 6);
Screw bolt, screw nail and bolt that the standard is applicable to:
Coarse Thread M1.6~M39; Fine Thread M8×1-M39×3;
Regular screw threads meeting GB/T192;
Diameter and pitch combination meeting GB/T 193;
Basic size meeting GB/T 196;
Tolerance and coordination meeting GB/T 197;
Products made of carbon steel or alloy steel.
The standard is not applicable to set screws and similar tensile-free threaded fasteners.
Following performance requirements are not specified in this standard:
Solderability;
Corrosion resistance (GB/T 3098.6);
Performance requirement under the working temperature higher than +300℃ (250℃ for 10.9 level steel) or lower than - 50℃;
Shear-resistant stress;
Fatigue resistance
Note: As for limit specifications larger than that specified in this Chapter, like d>39 mm, if the performance can meet all requirements, the symbolizing system may be adopted for these limit specifications.
2. Normative Reference
The following standards contain provisions which, through reference in this text, constitute provisions of this standard. All the Standards stated below are effective at the publication of this Standard. All standards are subject to revision, and parties to agreements based on this standard are encouraged to investigate the possibility of applying the latest editions of the standards indicated below.
Contents
Foreword
ISO Foreword
1. Scope
2. Normative Reference
3. Symbolizing System
4. Material
5. Mechanical/Physical Property
6. Test Item for Mechanical/physical Properties
7. Mini Tensile Load and Guarantee Load
8. Test Method
8.1 Tension Test of Mechanical Processing Test Piece
8.2 Object Tension Test of Bolt, Screw and Stud
8.3 Torque Test
8.4 Hardness Test
8.5 Object Guarantee Load Test of Bolt, Screw and Stud
8.6 Wedge Load Test for Bolt and Screw (excluding Stud)
8.7 Impact Test for Mechanical Processing Test Piece
8.8 Header Consistency Test for bolt and screw object which the diameter is less than or equal to 10 mm, and the length is too small to take out the test
8.9 Decarburization Test: Surface Carbon Potency Evaluation
8.10 Retempering Test
8.11 Surface Imperfection Inspection
9. Marking
9.1 Identification Mark of Manufacturer
9.2 Performance Rate Marking
9.3 Identification
9.4 Left-hand Thread Marking
9.5 Marks Selection
9.6 Package Identification
Appendix A
