S-91251A220 5-40 x 3" ASTM A574 Alloy Steel Socket Head Screws
Alloy Steel Socket Head Screws
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Basic Information
Head Parameters
Dimensions
Thread Parameters
Tip & Drive Parameters
Material & Strength
Temperature & Environment
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Key Features & Benefits at a Glance
- Exceptional tensile strength of 170,000 psi for reliable performance in high-stress applications
- Precision Class 3A thread fit ensures secure fastening and vibration resistance in demanding environments
- Black-oxide coating on alloy steel provides corrosion resistance and enhanced durability
- Rockwell C37 hardness maintains structural integrity under heavy loads and repeated use
- Hex socket drive design allows for easy installation with standard tools in confined spaces
- Full threading along the 3" length offers maximum grip and adjustability in assembly
- Compliance with ASTM A574, RoHS 3, and REACH ensures safety and regulatory adherence for industrial use
Professional Applications & Engineering Value
This 5-40 UNC thread socket head cap screw is engineered to address critical challenges in industrial settings, such as vibration loosening and material fatigue. The black-oxide alloy steel construction provides a protective layer against corrosion, extending service life in harsh conditions. With a coarse thread spacing and Class 3A fit, it delivers superior holding power in machinery, automotive assemblies, and heavy equipment. The hex drive and standard socket head profile facilitate quick, tool-friendly installation, reducing downtime. Ideal for applications requiring high tensile strength and precise thread engagement, this screw ensures long-term reliability in demanding engineering projects.
Specification Summary & Compliance
This product features a 5-40 UNC thread with Class 3A fit for precise dimensional accuracy and tight tolerances. It meets ASTM A574 specifications for high-strength socket head cap screws and is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and material integrity. Manufactured in the inch system, it includes a right-hand thread direction and coarse spacing for robust performance in industrial fastening applications.
