S-91274A156 1/4"-20 x 1/2" ASME B18.3, ASTM A574, ASTM B117 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 in high-stress applications, reducing the risk of fastener failure.
- Superior corrosion resistance from the zinc-flake coating protects against harsh industrial environments, extending service life.
- Precise Class 3A thread fit provides consistent, secure engagement with mating parts, minimizing assembly issues.
- High hardness (Rockwell C37) offers excellent wear resistance, maintaining fastener integrity through repeated use.
- Hex socket drive design allows for easy installation and high torque application in confined spaces.
- Compliance with major standards including ASME B18.3 and ASTM A574 guarantees quality and interchangeability.
- RoHS 3 and REACH compliance ensures environmental safety and regulatory acceptance for global markets.
Professional Applications & Engineering Value
This 1/4"-20 UNC Socket Head Cap Screw delivers critical engineering value in demanding applications where failure is not an option. Manufactured from zinc-flake-coated alloy steel, it solves common industrial pain points like corrosion-induced degradation and insufficient clamping force. The coarse thread spacing and Class 3A thread fit enable quick, reliable assembly in machinery, automotive systems, and heavy equipment, reducing downtime. The fully threaded design ensures maximum grip across the entire length, while the hex drive accommodates high-torque tools for secure fastening in tight spaces. Ideal for OEM and MRO applications requiring high tensile strength and long-term durability.
Specification Summary & Compliance
This socket head cap screw features a 1/4"-20 UNC thread with Class 3A precision fit and coarse thread spacing. It meets ASME B18.3 for dimensional consistency and ASTM A574 for material quality. The zinc-flake coating is tested per ASTM B117 for corrosion resistance. Fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental and safety standards are met.
