S-91255A578 5/16"-18 x 1/2" ASTM F835 Steel Button Head Hex-Drive Screws
Steel Button Head Hex-Drive 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
- Superior corrosion protection with Black-Oxide coating, extending service life in demanding environments
- Exceptional mechanical strength from alloy steel construction, rated at 120,000 psi tensile strength for heavy-duty applications
- Precise thread engagement with Class 3A fit, ensuring reliable fastening and vibration resistance
- Optimized drive efficiency with 3/16" hex drive and rounded button head, allowing for easy installation in confined spaces
- Enhanced durability with Rockwell C39 hardness, maintaining structural integrity under high stress
- Wide compatibility through 5/16"-18 UNC coarse threading, suitable for various industrial assemblies
- Regulatory compliance assurance meeting ASME B18.3, ASTM F835, RoHS 3, and REACH standards for global use
Professional Applications & Engineering Value
This Black-Oxide alloy steel rounded head hex screw addresses critical industrial challenges where corrosion resistance, high tensile strength, and precise threading are paramount. The fully threaded 5/16"-18 UNC coarse thread design ensures maximum grip in metal-to-metal assemblies, machinery, and structural frameworks, reducing the risk of loosening under dynamic loads. The rounded button head profile combined with a hex drive provides a low-profile, flush finish that minimizes protrusion hazards while enabling efficient torque application. Engineered to withstand harsh operational conditions, these screws deliver long-term reliability in automotive, construction, and heavy equipment sectors where Class 3A thread fit guarantees consistent performance and reduced maintenance intervals.
Specification Summary & Compliance
Manufactured to exacting standards with Class 3A thread fit and UNC coarse threading for optimal engagement. Complies with ASME B18.3 and ASTM F835 specifications for dimensional accuracy and mechanical properties. Meets environmental regulations including RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliance, ensuring safe use in regulated industries.
