S-91251A446 1/4"-28 x 1 1/2" 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 failure risks in demanding applications.
• Precision Class 3A thread fit provides superior engagement and vibration resistance, minimizing loosening in critical assemblies.
• Black-oxide finish on alloy steel enhances corrosion resistance and durability, extending service life in harsh industrial environments.
• Fine UNRF threads offer improved load distribution and sealing capabilities compared to coarse threads, ideal for precision equipment.
• Partially threaded design allows for secure clamping without unnecessary thread engagement, optimizing installation efficiency.
• Rockwell C37 hardness balances toughness and machinability, resisting wear while maintaining ease of use.
• 3/16" hex drive socket head enables high-torque installation with standard tools, reducing stripping and improving assembly speed.

Professional Applications & Engineering Value

Engineered for precision and reliability, this Black-Oxide Alloy Steel Socket Head Cap Screw addresses critical needs in high-performance machinery, automotive systems, and aerospace components. The UNRF Class 3A fine threads ensure tight tolerances and superior vibration resistance, preventing joint failure in dynamic loads. With a 170,000 psi tensile strength and Rockwell C37 hardness, it withstands extreme mechanical stress while the black-oxide coating provides essential corrosion protection. The partially threaded configuration allows precise clamping in confined spaces, making it ideal for motor mounts, precision instruments, and heavy-duty equipment where ASTM A574 compliance guarantees consistent quality and performance.

Specification Summary & Compliance

This socket head cap screw adheres to Class 3A thread fit for precise engagement and meets ASTM A574 specifications for high-strength fasteners. It is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety. Manufactured in the inch system with a 1/4"-28 UNRF fine thread and 1" minimum thread length, it delivers consistent dimensional accuracy for industrial applications.