S-91251A126 5-40 x 3/8" 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 provides reliable performance in high-stress applications, reducing the risk of fastener failure.
- Superior corrosion resistance from the black-oxide finish extends service life in harsh industrial environments, minimizing maintenance needs.
- Precise Class 3A thread fit ensures tight, secure connections with minimal backlash, enhancing assembly accuracy and stability.
- High hardness (Rockwell C37) offers excellent wear resistance, maintaining thread integrity through repeated use and adjustments.
- Coarse UNC threads allow for quick installation and removal, saving time in maintenance and production workflows.
- Hex socket drive design enables easy access in confined spaces and provides high torque transmission without slippage.
- Full threading along the 3/8" length ensures consistent grip and load distribution, ideal for varied clamping requirements.
Professional Applications & Engineering Value
This black-oxide alloy steel socket head cap screw is engineered to address critical challenges in demanding sectors such as machinery assembly, automotive systems, and heavy equipment. The 5-40 UNC coarse thread with Class 3A fit delivers reliable engagement in materials prone to vibration, preventing loosening under dynamic loads. Its 170,000 psi tensile strength and Rockwell C37 hardness provide durability against shear and fatigue, making it suitable for high-stress fastening where precision and longevity are paramount. The black-oxide surface treatment not only resists corrosion but also reduces galling, ensuring smooth installation in repetitive or automated processes. By integrating these features, this screw minimizes downtime and enhances structural integrity in industrial applications.
Specification Summary & Compliance
This socket head cap screw adheres to ASTM A574 specifications, ensuring consistent quality and performance. Thread dimensions follow 5-40 UNC coarse thread standards with a Class 3A fit for precise tolerance. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, supporting environmentally responsible sourcing and use in global markets.
