S-91251A551 1/4"-20 x 2 1/4" 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 in high-stress applications, reducing the risk of fastener failure.
- Superior corrosion resistance from the black-oxide finish prolongs service life in harsh industrial environments, minimizing maintenance needs.
- Precise Class 3A thread fit provides consistent engagement and vibration resistance, enhancing assembly reliability.
- Partially threaded design allows for controlled clamping force and easier alignment in specific mounting scenarios.
- High hardness (Rockwell C37) offers excellent wear resistance, maintaining thread integrity through repeated use.
- Coarse UNRC thread enables quick installation and reduced cross-threading risk, saving valuable assembly time.
- Compliance with ASTM A574, RoHS 3, and REACH ensures material consistency and environmental safety for global supply chain integration.
Professional Applications & Engineering Value
This black-oxide alloy steel socket head cap screw is engineered to address critical challenges in heavy-duty machinery, automotive assemblies, and precision equipment. The high tensile strength and Rockwell C37 hardness provide resilience against dynamic loads and wear, while the coarse UNRC thread and Class 3A fit ensure secure fastening in vibrating environments. The partially threaded shank design allows for optimal stress distribution, preventing joint loosening. Ideal for applications demanding corrosion resistance and durability, such as industrial robots, construction equipment, and aerospace components, this screw delivers consistent performance under extreme conditions, reducing downtime and maintenance costs.
Specification Summary & Compliance
This screw adheres to Class 3A thread tolerance for precision fit and UNRC coarse thread standards. Manufactured in compliance with ASTM A574 specifications, it ensures material integrity and performance. The product is verified as RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, meeting stringent environmental and safety regulations for industrial use.
