S-91670A713 1/2"-13 x 1" ASTM A574 Left-Hand Threaded 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.
• Left-hand thread design provides secure fastening in applications where right-hand rotation could cause loosening, ideal for specific machinery and rotating equipment.
• Class 3A thread fit offers tighter tolerances for superior thread engagement and vibration resistance in precision assemblies.
• Black-oxide coating on alloy steel enhances corrosion resistance and provides a durable, wear-resistant finish for extended service life.
• Coarse UNC threading allows for quicker installation and reduced cross-threading risk, improving assembly efficiency.
• 3/8" hex drive socket head enables high-torque application with standard tools, ensuring secure installation in confined spaces.
• Full threading along the 1" length provides consistent clamping force and flexibility in various material thicknesses.

Professional Applications & Engineering Value

Engineered for demanding industrial environments, this Black-Oxide Alloy Steel Socket Head Cap Screw combines high tensile strength and Rockwell C37 hardness to withstand extreme mechanical loads and vibrations. The left-hand thread is critical in applications where reverse-threading prevents unintended loosening, such as in rotating shafts, presses, and machinery with counter-clockwise motion. Its coarse UNC thread and Class 3A fit ensure precise alignment and robust fastening, reducing assembly errors and maintenance downtime. The black-oxide surface treatment not only resists corrosion but also minimizes galling, making it suitable for automotive, aerospace, and heavy equipment industries where reliability and compliance with ASTM A574 are paramount.

Specification Summary & Compliance

This socket head cap screw adheres to inch system dimensions with a 1/2"-13 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 manufacturing quality. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, supporting safe and environmentally responsible industrial use.