Materials
Alloy Steels: A194 (2H, 2HM, 7, 7M)
ASTM A194 Grade 2H
Manufacturing Considerations:
Made from carbon steel or alloy steel, quenched & tempered.
Straightforward machining and heat treat process; widely available.
Performance in Fasteners:
High-strength nut used with A193 B7 bolts and studs.
Standard for pressure vessels, flanges, valves, and fittings.
Workhorse grade in oil & gas, petrochemical, and power.
ASTM A194 Grade 2HM
Manufacturing Considerations:
Same base material as 2H, but heat treated to lower hardness.
Requires precise control to balance strength with reduced hardness.
Performance in Fasteners:
Designed for use with A193 B7M studs.
Lower hardness mitigates sulfide stress cracking (SSC) and hydrogen embrittlement.
Critical for sour service and corrosive environments.
ASTM A194 Grade 7
Manufacturing Considerations:
Alloy steel, quenched & tempered (similar chemistry to A193 B7).
Good machinability and strong dimensional stability after heat treatment.
Performance in Fasteners:
Used with A193 B16 studs and bolts.
Provides high strength at elevated temperatures.
Common in steam turbines, power plants, and high-temperature systems.
ASTM A194 Grade 7M
Manufacturing Considerations:
Variant of Grade 7, heat treated to lower hardness.
Requires precise heat control and testing.
Performance in Fasteners:
Used with A193 B16M or where corrosive/high H₂S service overlaps with high temp.
Reduces cracking risk in sour service applications while maintaining high-temp capability.
Key Takeaway in Engineered Fasteners
2H: Standard high-strength nut (pairs with B7).
2HM: Sour service version of 2H (pairs with B7M).
7: High-temp alloy nut (pairs with B16).
7M: Sour-service version of Grade 7 (pairs with B16M).
Materials
BRASS
BRONZE
COPPER
PH STAINLESS STEEL
DOING WHATEVER IT TAKES
Putting Manufacturing Exellence Into Practice
The manufacturing processes, testing capabilities, and quality systems featured throughout WN Global support the production of critical components and engineered fastening solutions across demanding industries. Connect with our team to learn how our manufacturing capabilities can support your project requirements.
