S-91251A030 1/2"-20 x 4 1/2" 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 ensures reliable performance under high-stress conditions, reducing the risk of fastener failure in critical assemblies.
- Corrosion-resistant black-oxide coating on alloy steel provides enhanced durability and longevity, even in demanding industrial environments.
- Precision Class 3A thread fit offers superior engagement and vibration resistance, minimizing loosening in dynamic applications.
- Hex socket drive design allows for high-torque installation and removal in confined spaces, improving assembly efficiency.
- Partially threaded shank provides unthreaded bearing surface for precise clamping force distribution and alignment.
- Compliance with ASTM A574 guarantees consistent quality and mechanical properties for engineering reliability.
- RoHS 3 and REACH compliance ensures environmental safety and regulatory adherence for global supply chains.
Professional Applications & Engineering Value
Engineered for high-performance industrial applications, this black-oxide alloy steel socket head cap screw addresses common challenges in machinery, automotive, and heavy equipment assembly. The fine UNRF thread and Class 3A fit deliver exceptional clamping force and vibration resistance, preventing joint failure in high-cycle operations. Its corrosion-resistant coating extends service life in humid or chemically exposed settings, while the hex drive facilitates secure installation with standard tools. Ideal for precision fixtures and structural frameworks, this fastener ensures reliable performance where high tensile strength and dimensional accuracy are critical to operational safety and efficiency.
Specification Summary & Compliance
This socket head cap screw features a 1/2"-20 UNRF thread with Class 3A tolerance for precise fit, a partially threaded design with minimum 1 1/2" thread length, and a 4 1/2" overall length. Manufactured to ASTM A574 specifications, it meets rigorous mechanical standards including Rockwell C37 hardness. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental and safety adherence for industrial use.
