The widespread application and importance of stainless steel bolts are self-evident. In the bolt market, stainless steel bolts account for a large proportion, so it is necessary to establish and follow standards for stainless steel bolts. This article will provide a detailed introduction to the standards, specifications, and standard specifications for stainless steel bolts.
Standard for stainless steel bolts
The standard for stainless steel bolts can refer to the standard for carbon steel bolts. Specifically, according to international standards such as GB/T6170-2000 and GB/T5782-2000, the mechanical property level code for stainless steel bolts and nuts is A2-70 (0r18Ni9); A4-70 (0Cr17Ni12Mo2).
Standard for stainless steel bolts - Standard specifications
High strength steel bolt and grades are used for steel structure nodes. This specification covers two types of quenched and tempered alloy steel, used for large hexagonal bolts in structures, with a tensile strength of 1040-1210 MPa. The American Institute of Architectural and Industrial Fasteners Association has approved the use of ASTM A325 and A 490 bolts for steel structure connections, which can be used for structural purposes.
Bolt specifications include bolt diameter M12 to M36. They specify the type to indicate the chemical composition as follows: Type 1 Medium carbon alloy steel. This specification is applicable to the use of ASTM A 325 and A 490 large hexagonal structural bolts by the Research Committee in its published steel structure specifications.
This standard stipulates that the English/pound system is considered the only unit of measurement. There are no other units of measurement included in the standard. This standard is not intended to address all safety hazards, and if any, it is not relevant to this standard. It is the responsibility of users to determine the applicability and limitations of appropriate safety and health practices established by this standard before use.
The American Society for Testing and Materials standard A325 is a heat-treated high-strength steel structural bolt with a minimum tensile strength of 120/105 kilobars per square inch. The A 490 specification is 10.9 and 10.9.3 high-strength bolts, which are used for steel structure joints. The A 563M Specification for Carbon and Alloy Steel Nuts (Metric) is A563M carbon and alloy steel nuts (metric). The nut meets the requirements of A563M specification and is used in conjunction with the large hexagonal bolt specification A 490M. The various requirements for the surface finish of nuts are as follows: Bolt Type and Finish Bolt Type Nut Class and Finish The final selection of nuts.
The alloy recognized by the American Institute of Steel is within the maximum range of alloys. Elements exceeding one or more of the following ranges: manganese, 1.65%. Copper, 0.60%; Silicon, 0.60%; Or any specified element within a certain range or a clear minimum order quantity limit, requiring the addition of recognized structural alloy steel, aluminum, chromium to 3.99%, cobalt, column, molybdenum, nickel titanium, tungsten, vanadium, zirconium, or any other alloying element to obtain the required alloying effect. M24, with a smaller bolt diameter, has a length ranging from 21.4 D to 2D, but cannot do so. The tensile test should be conducted using a wedge to determine the magnitude of axial tension, and should comply with the minimum tensile load and proof load, or the proxy proof load specified in Table 4. The bolt has a small diameter and a length of M24 shorter than 2D, which should be based on the hardness of the axial tensile test. After completing the hardness and tension tests on these two pairs of bolts as required, record the first low hardness reading that occurred. The purpose of this experiment is to evaluate the presence of determined complete and incomplete decarburization and core hardness near different surfaces, and optimize them to improve the quality and performance of stainless steel bolts.
In summary, the formulation and adherence to stainless steel bolt standards are key to ensuring the quality and performance of stainless steel bolts, as well as ensuring the safety of use and the stability of industrial infrastructure. Therefore, studying, mastering, and implementing these standards and specifications is one of the important tasks for industrial manufacturers and related institutions, providing users with higher quality and more reliable stainless steel bolt products.
