S-91670A319 10-32 x 1 1/2" 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 in high-stress applications, reducing the risk of fastener failure.
• Superior corrosion resistance from the Black-Oxide coating extends service life in harsh industrial environments, minimizing maintenance needs.
• Precise Class 3A thread fit provides tighter tolerances for secure, vibration-resistant assemblies in critical machinery.
• Left-hand thread design offers specialized functionality for applications requiring reverse threading to prevent loosening under counter-clockwise rotation.
• High hardness rating (Rockwell C37) enhances durability and wear resistance, maintaining thread integrity through repeated use.
• 5/32" hex drive socket allows for easy installation with standard tools in confined spaces, improving assembly efficiency.
• Full thread coverage along the 1-1/2" length ensures consistent clamping force and versatility across various material thicknesses.

Professional Applications & Engineering Value

This Black-Oxide Alloy Steel Socket Head Cap Screw is engineered to address critical challenges in industrial and automotive assemblies where reverse threading and high vibration resistance are paramount. The left-hand UNF fine threads with Class 3A fit prevent unintentional loosening in rotating equipment, while the high tensile strength and Rockwell C37 hardness ensure longevity under dynamic loads. The corrosion-resistant Black-Oxide finish protects against degradation in exposed or humid conditions, making it ideal for precision machinery, automotive components, and heavy-duty fixtures. Its socket head design with a 5/32" hex drive facilitates secure tightening in tight spaces, enhancing installation safety and efficiency for maintenance professionals.

Specification Summary & Compliance

This screw features a 10-32 UNF left-hand thread with Class 3A thread fit and fine thread spacing for precision assembly. It meets ASTM A574 specifications for high-strength 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, confirming its safety for use in regulated industries without hazardous substances.