S-91251A154 1"-8 x 3 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 and heavy-duty industrial applications.
• Superior corrosion resistance provided by the black-oxide finish, extending service life in demanding environments.
• Precise Class 3A thread fit guarantees secure, vibration-resistant connections with minimal risk of loosening.
• High Rockwell C37 hardness offers excellent wear resistance and durability under repetitive loads.
• 3/4" hex drive design allows for high-torque installation and removal with standard tools, improving assembly efficiency.
• Coarse 1"-8 UNRC threads enable quick engagement and are less prone to clogging in dirty or debris-filled conditions.
• Compliance with ASTM A574, RoHS 3, and REACH ensures material consistency, environmental safety, and regulatory acceptance for global projects.

Professional Applications & Engineering Value

This Black-Oxide Alloy Steel Socket Head Cap Screw is engineered to address critical challenges in heavy machinery, automotive assemblies, and structural frameworks where high tensile strength and vibration resistance are paramount. The alloy steel construction, combined with a Rockwell C37 hardness, prevents stripping and deformation under extreme loads, while the black-oxide surface treatment enhances corrosion protection without sacrificing dimensional integrity. Its 3/4" hex drive and coarse UNRC threads facilitate rapid installation in tight spaces, reducing downtime in production lines. Ideal for partially threaded applications requiring precise clamp load, this fastener delivers consistent performance in industrial screws and heavy-duty fasteners scenarios, ensuring long-term reliability and safety.

Specification Summary & Compliance

This socket head cap screw features a 1"-8 coarse UNRC thread with a Class 3A thread fit for high precision and minimal tolerance deviation. The partially threaded design includes a minimum thread length of 2 1/2" and an overall length of 3 3/4". Manufactured in compliance with ASTM A574 specifications, it meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) standards, ensuring adherence to environmental and safety regulations for industrial use.