S-91251A114 4-40 x 7/8" 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 under high-stress conditions, reducing the risk of fastener failure.
- Precise Class 3A thread fit provides superior engagement and vibration resistance, minimizing loosening in dynamic applications.
- Black-oxide coating on alloy steel offers enhanced corrosion resistance and a durable, non-reflective finish for harsh environments.
- Standard hex socket drive allows for easy installation with common tools, improving assembly efficiency and reducing downtime.
- Fully threaded design ensures consistent clamping force along the entire length, ideal for applications requiring uniform pressure distribution.
- Compliance with ASTM A574, RoHS 3, and REACH guarantees material quality and environmental safety, meeting strict industrial and regulatory standards.
- Rockwell C37 hardness provides excellent wear resistance, extending the screw's service life in demanding mechanical setups.
Professional Applications & Engineering Value
This 4-40 UNC thread socket head cap screw is engineered to address common industrial challenges, such as vibration-induced loosening and corrosion in machinery. Made from black-oxide alloy steel, it combines high tensile strength with a protective finish to withstand harsh conditions, including automotive assemblies and precision equipment. The coarse thread and Class 3A fit ensure secure fastening in materials prone to stress, while the hex drive design simplifies maintenance. Ideal for applications requiring reliable, high-strength fasteners, it reduces maintenance costs and enhances operational safety by preventing unexpected failures.
Specification Summary & Compliance
This screw features a 4-40 UNC coarse thread with Class 3A precision fit for tight tolerances, and dimensions including a 7/8" length and 3/32" hex drive. It meets ASTM A574 specifications for material quality, and is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and adherence to industrial standards.
