S-91571A326 7/8"-9 x 4" ASME B18.2.6, ASTM A325, ASTM F3125 Medium-Strength Steel Heavy Hex Head Screws for Structural Applications
Medium-Strength Steel Heavy Hex Head Screws for Structural Applications
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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 load-bearing capacity with 120,000 psi tensile strength for demanding structural and heavy machinery applications.
- Superior material hardness at Rockwell C19 ensures excellent wear resistance and long-term reliability under high stress.
- Optimized grip and thread design with a 2-1/2" grip length and coarse UNC threads for secure fastening in structural steel and construction assemblies.
- Precise thread fit with Class 2A tolerance ensures smooth assembly and consistent clamping force in high-vibration environments.
- Partial threading allows for unthreaded shank sections to bear shear loads effectively, enhancing joint integrity.
- Comprehensive compliance with ASME B18.2.6, ASTM A325, and ASTM F3125 standards guarantees interchangeability and performance in regulated industries.
- Environmental responsibility through RoHS 3 and REACH compliance, supporting sustainable procurement in global supply chains.
Professional Applications & Engineering Value
Engineered for structural steel connections, heavy construction, and industrial machinery, this Grade A325 steel hex head screw addresses critical challenges like joint slippage and fatigue failure. Its coarse UNC thread and external hex drive enable rapid installation with standard tools, reducing assembly time in field applications. The partially threaded design concentrates tensile strength along the engaged portion while the unthreaded shank resists shear forces—ideal for beam splices and bracket mounting. Combined with high tensile strength and hardened steel composition, it ensures reliable performance in dynamic loads and harsh environments, minimizing maintenance and replacement costs.
Specification Summary & Compliance
This screw maintains Class 2A thread fit per UNC standards, ensuring dimensional accuracy for consistent engagement. Manufacturing adheres to ASME B18.2.6, ASTM A325, and ASTM F3125 specifications, covering material composition and mechanical properties. It is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming the absence of restricted substances for safe use in international markets.
