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Standard Specification for ASTM A194 Grade 8

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On 2024-12-22
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Grade A194 Grade 8
UNS S30400
Other name Type 304
Standard ASTM A194/194M-2016
Carbon steel, Alloy steel, and Stainless steel nuts for bolts for high pressure or high temperature service, or both
Classification Austenitic stainless steel
Label Corrosion and weldability resistance
Introductions Process: Stainless steel used to manufacture Grade 8 nuts shall be manufactured by electric arc furnace using one of the following processes (separate deoxidation and refining are optional); Vacuum induction furnace; After any of the above manufacturing processes, electroslag remelting or consumable arc remelting is carried out. Steel mills shall have adequate controls to eliminate excessive non-uniformity, non-metallic inclusions, shrinkage, porosity and other defects.
8 The nut shall be made of hot forging or cold heading, or from hot forging, hot rolled or cold drawn bar material.
Material profile: S30400 is a typical low-carbon austenitic stainless steel, which is further reduced carbon content on the basis of 302, has good processing and molding properties and oxidation resistance, has strong corrosion resistance to oxidizing acids (such as nitric acid), and has certain corrosion resistance to alkali solutions and most organic and inorganic acids. Intergranular corrosion resistance is better than 302 with higher carbon content, but it still has a tendency of intergranular corrosion when working in water and steam for a long time. The steel has good weldability. Austenitic stainless steel cannot be strengthened by heat treatment and can only be strengthened by work hardening. S30400 has stable oxidation resistance in hot air below 900°C, and good corrosion resistance to nitric acid, sulfuric acid, acetic acid, oxalic acid and phosphoric acid. Intergranular corrosion damage may occur when parts work in corrosive medium, water or steam medium for a long time.
Scope of application of this standard
① This standard is applicable to all kinds of carbon steel, alloy steel and martensitic stainless steel nuts of 1/4 to 4 inches and M6 to M100. Also applicable to austenitic stainless steel nuts of 1/4 inch and M6 and above. These nuts are suitable for high or high pressure or high temperature and high pressure environments. Nut grades may not be changed without Buyer’s permission.
② The bar material for making nuts should be hot forged. The material can be further processed by centerless grinding or cold drawing. Austenitic stainless steels can be solution treated or annealed and strain hardened. When ordering annealed and strain-hardened austenitic stainless steel in accordance with Supplemental Requirement S1, Buyer shall take special care to fully understand the contents of Supplemental requirement S1 and Appendix X1.
Supplementary requirements are optional and apply only if specified in the inquiry, contract and order.

 

A194 Grade 8 Chemical Element Content (%)
Constituent C Si Mn P S Cr Ni
Min – – – – – 18 8
Max 0.08 1 2 0.045 0.03 20 11
• Intentional addition of Bi, Se, Te and Pb is not allowed except for 6F, 8F and 8FA grades where Se is required.
• Elements not listed in the table Mo, Ti, Cb, N have no requirements and do not need to be determined and reported.

 

A194 Grade 8 Mechanical properties
Products Hardness
HRB
Finished nut 126~300HBW
≤32HRC
≥60HRB

 

China Taiwan, China Japan Korea America The International Standard Organization Germany France European standard Russia Sweden United Kingdom
GB ISC CNS JIS KS ASTM UNS ISO Numerical grade DIN EN/DIN W-Nr. NF EN/NF EN Numerical grade GOST SS BS EN/BS
06Cr19Ni9 S30408 304 SUS 304 STS 304 304 S30400 X5CrNi 18-10 4301-304-00-I X5CrNi 18-10 1.4301 Z6CN 18-09 X5CrNi 18-10 1.4301 08Х18Н10 2332 304S15
(X5CrNi 18-9) 2333
Newer Standard Specification for ASTM A194 Grade 8MN
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Older Standard Specification for A194 Grade 7M

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