S-91274A204 1/4"-20 x 4" 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 provided by the zinc-flake coating extends service life in harsh industrial environments.
- Precise Class 3A thread fit guarantees secure, vibration-resistant assemblies with minimal risk of loosening.
- Partially threaded design allows for optimal clamping force distribution and easier alignment during installation.
- High hardness (Rockwell C37) enhances wear resistance and maintains thread integrity under repeated use.
- Hex drive compatibility with a 3/16" drive size enables efficient installation and removal with standard tools.
- Compliance with major standards including ASME B18.3 and ASTM A574 ensures consistent quality and interoperability.
Professional Applications & Engineering Value
This 1/4-20 UNC Socket Head Cap Screw is engineered to address critical challenges in demanding industrial settings. The zinc-flake-coated alloy steel construction provides excellent protection against corrosion, making it ideal for machinery, automotive assemblies, and outdoor equipment exposed to moisture or chemicals. The coarse UNC thread and Class 3A thread fit deliver superior holding power and vibration resistance, reducing maintenance needs in dynamic applications. Its partially threaded shank allows for precise clamping without compromising structural integrity, while the hex drive socket head ensures easy access in confined spaces. These features collectively enhance reliability and longevity in heavy-duty fastening scenarios, supporting efficient production and reduced downtime.
Specification Summary & Compliance
This screw adheres to Class 3A thread fit for high precision and meets ASME B18.3, ASTM A574, and ASTM B117 specifications, ensuring consistent dimensional accuracy and performance. It is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, supporting environmentally responsible manufacturing and use in global markets.
