ASTM A193 Grade B7m Bolt, Nuts, Washers Manufacturer in India

ASTM A193 Grade B7m, ASTM A193 Grade B7m Bolt, Nuts, ASTM A193 Bolt Manufacturer in India – Ananka Group

ASTM A193 Grade B7M is chromium-molybdenum alloy steel bolting materials specification with use under moderate to high temperatures in corrosive environments. Grade B7M is similar to the ASTM A193 Grade B7, but further processed for more considerable resistance to stress corrosion cracking and hydrogen embrittlement. Because this service is better suited for even more aggressive chemical environments than Grade B7, it is used extensively throughout the oil and gas, petrochemical, and offshore industries.

ASTM A193 Grade B7M: Chemical Composition and Specification of Bolts

ASTM A193 Grade B7M bolts are made from chromium-molybdenum alloy steel. The primary elements are composed of the following:

Chromium: 0.80-1.10%

Molybendenum: 0.15-0.25%

Carbon: 0.28-0.45%

The most significant differences between Grade B7 and B7M bolts are the mechanical properties. 

It can be said that in general, the hardness levels of B7M bolts are lower than B7 bolts with the purpose of minimizing the risk of stress corrosion cracking.

Moreover, these B7M bolts go through thorough testing for more severe conditions regarding environmental and performance in corrosive exposure.

Benefits of ASTM A193 Grade B7M Bolts

Resistance to Stress Corrosion Cracking Improved: Although B7M bolts have lower hardness levels than standard B7 bolts, in sour gas or chloride-containing environments, B7M outperforms standard B7 bolts where stress corrosion cracking is an issue.

Strength up to High Temperature: Grade B7M retains sound mechanical strength and stability at elevated temperatures. Such bolting can be used in pressure vessels, heat exchangers, and boilers.

Resistance to Corrosion: Chromium and molybdenum contents in B7M bolts provide excellent resistance properties against corrosion in mildly corrosive conditions, such as those prevailing in oil refineries and chemical processing plants.

Low Hardness Needs: ASTM A193 Grade B7M requires minimum hardness compared with B7, thus helping to reduce hydrogen embrittlement that may prevail in wet or corrosive conditions.

General Use:

• Oil and gas industry, specially in sour gas (H₂S) conditions
• Petrochemical Plants and Refineries
• Offshore Platforms and Marine applications
• High-pressure, High-temperature (HPHT) environments
• Valves, Flanges, and Pressure Vessels

ASTM A193 Grade B7M is a specification made to provide better resistance to stress corrosion cracking and hydrogen embrittlement while retaining strength at elevated temperatures. They are particularly used in corrosive or sour gas service where these modes of failure are applicable.

ASTM A193 Grade B7m Chemical Composition

ASTM A193 Grade B7m Mechanical Composition