S-91251A366 7/16"-20 x 3/8" ASTM A574 Alloy Steel Socket Head Screws

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 in critical assemblies.
• Superior thread precision with Class 3A fit provides tighter tolerances and improved vibration resistance, enhancing joint integrity in precision machinery.
• Corrosion-resistant black-oxide coating extends service life by protecting against rust and wear in harsh industrial environments.
• High hardness rating (Rockwell C37) offers excellent wear resistance, maintaining dimensional stability and reducing replacement frequency.
• Fine thread design (UNF 7/16"-20) allows for finer adjustment and better clamping force distribution in compact or high-vibration applications.
• Full threading along the entire 3/8" length enables versatile installation depth and secure fastening across varying material thicknesses.
• Compliance with ASTM A574, RoHS 3, and REACH ensures material consistency, environmental safety, and global regulatory acceptance for industrial use.

Professional Applications & Engineering Value

Engineered for demanding industrial settings, these black-oxide alloy steel socket head cap screws address common challenges like vibration loosening and corrosion in machinery, automotive, and heavy equipment assemblies. The Class 3A UNF fine threads provide superior clamp load retention and precise alignment, critical for high-stress connections where reliability is paramount. Combined with the 170,000 psi tensile strength and corrosion-resistant coating, they minimize maintenance downtime and extend equipment lifespan. Ideal for tight-clearance applications requiring a 3/8" hex drive, these screws deliver consistent performance in aerospace, manufacturing, and precision engineering projects, ensuring secure fastening without compromising on durability or compliance.

Specification Summary & Compliance

This socket head cap screw features a 7/16"-20 UNF fine thread with Class 3A fit for high precision and vibration resistance. Dimensions include a 3/8" length, 21/32" head diameter, and 7/16" head height with a standard socket profile. Manufactured to ASTM A574 specifications, it meets stringent material and performance criteria. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006), ensuring adherence to environmental and safety regulations for industrial use.