S-91251A630 3/8"-16 x 1 3/4" ASTM A574 Alloy Steel Socket Head Screws

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 on alloy steel, extending service life in demanding industrial environments.
• Precise Class 3A thread fit provides tighter tolerances for secure, vibration-resistant assemblies in critical machinery.
• High hardness rating (Rockwell C37) enhances wear resistance, maintaining thread integrity through repeated use and adjustments.
• 5/16" hex drive design allows for easy installation and high torque application with standard tools, improving assembly efficiency.
• Partially threaded shank offers optimal grip and clamping force control, ideal for components requiring precise alignment.
• Compliance with ASTM A574, RoHS 3, and REACH ensures material consistency and environmental safety for global supply chains.

Professional Applications & Engineering Value

Engineered for heavy-duty industrial applications, this black-oxide alloy steel socket head cap screw addresses common challenges like vibration loosening and corrosion in machinery, automotive, and construction equipment. The 3/8"-16 UNC coarse thread with Class 3A fit ensures rapid assembly and reliable holding power, minimizing downtime. Its high tensile strength and Rockwell C37 hardness provide durability under dynamic loads, while the black-oxide surface treatment resists rust in humid or abrasive conditions. Ideal for use in precision assemblies where partially threaded designs prevent over-tightening and distribute stress evenly, enhancing the longevity of connected components.

Specification Summary & Compliance

This screw adheres to inch system measurements with a 3/8"-16 UNC coarse thread and Class 3A thread fit for high precision. It meets ASTM A574 specifications for alloy steel socket head cap screws, ensuring consistent material properties and manufacturing quality. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, it is free from hazardous substances, supporting safe and sustainable industrial operations.