S-91670A626 3/8"-16 x 1 1/4" 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 threads may loosen due to rotational forces, enhancing operational safety.
• Black-oxide coating on alloy steel offers superior corrosion resistance, extending service life in harsh industrial environments.
• Class 3A thread fit delivers precise, tight tolerances for improved assembly accuracy and vibration resistance.
• 5/16" hex drive socket head allows for easy installation and removal with standard tools, minimizing downtime during maintenance.
• Rockwell C37 hardness ensures high durability and wear resistance, maintaining integrity through repeated use.
• Compliance with ASTM A574, RoHS 3, and REACH guarantees adherence to industry standards for quality and environmental safety, supporting regulatory requirements.

Professional Applications & Engineering Value

This left-hand thread socket head cap screw is engineered to address critical challenges in machinery and equipment where reverse rotation is a concern. Made from black-oxide alloy steel, it combats corrosion and wear in demanding settings like automotive assemblies, heavy-duty manufacturing, and aerospace systems. The UNC coarse thread and Class 3A fit provide secure, vibration-resistant connections, preventing unintentional loosening in high-torque applications. Its high tensile strength and Rockwell C37 hardness ensure long-term reliability, reducing maintenance needs and downtime. Ideal for industrial fastening in environments requiring left-hand threading, this screw delivers consistent performance while meeting strict ASTM A574 specifications for quality assurance.

Specification Summary & Compliance

This screw adheres to precise dimensional standards, including a Class 3A thread fit for tight tolerances and UNC coarse threads with a 3/8"-16 size. It meets ASTM A574 manufacturing specifications for high-strength socket head cap screws, ensuring consistent quality. Compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations confirms its environmental safety, free from hazardous substances, making it suitable for global industrial use.