S-91251A426 3/8"-24 x 1 1/4" 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.
• Corrosion-resistant black-oxide finish on alloy steel enhances durability and longevity in harsh industrial environments.
• Precision Class 3A thread fit provides superior engagement and vibration resistance for secure, long-lasting assemblies.
• Fine UNF threads (3/8"-24) offer improved load distribution and better sealing capabilities compared to coarse threads.
• Fully threaded design allows for maximum adjustability and holding power along the entire screw length.
• 5/16" hex drive socket head enables easy installation with standard tools, even in confined spaces.
• Compliance with ASTM A574, RoHS 3, and REACH ensures material quality and environmental safety for global applications.

Professional Applications & Engineering Value

These black-oxide alloy steel socket head cap screws are engineered to address critical challenges in precision machinery, automotive assemblies, and heavy equipment. The Class 3A UNF fine threads provide exceptional clamp load retention and resistance to loosening under vibration, making them ideal for dynamic load applications. The Rockwell C37 hardness combined with 170,000 psi tensile strength ensures these fasteners maintain integrity in high-stress environments where failure is not an option. The corrosion-resistant black-oxide surface treatment extends service life in moderately corrosive conditions without compromising dimensional accuracy. These fully threaded screws with 5/16" hex drive offer reliable performance in automated assembly systems and maintenance applications requiring consistent torque values and repeatable fastening solutions.

Specification Summary & Compliance

This socket head cap screw features precision 3/8"-24 UNF fine threads with Class 3A fit for tight tolerance applications. Manufacturing complies with ASTM A574 specification for alloy steel socket head cap screws. The product meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliance requirements for environmental safety. Dimensions include 1-1/4" length, 9/16" head diameter, and 5/16" hex drive size with standard socket head profile and right-hand thread direction.