S-91251A617 5/8"-18 x 6" 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
• Superior corrosion resistance from the black-oxide coating extends service life in demanding industrial environments
• Precise Class 3A thread fit provides secure, vibration-resistant connections for critical assemblies
• Fine UNRF thread design offers improved load distribution and better sealing capabilities compared to coarse threads
• Rockwell C37 hardness rating maintains dimensional stability under heavy loads and repeated use
• 1/2" hex drive compatibility allows for high-torque installation with standard industrial tools
• Partially threaded design combines the benefits of both threaded and unthreaded sections for versatile clamping applications

Professional Applications & Engineering Value

These black-oxide alloy steel socket head cap screws deliver critical engineering solutions for industrial applications where high tensile strength and corrosion resistance are paramount. The 5/8"-18 UNRF fine thread configuration provides superior clamping force distribution in precision machinery, automotive assemblies, and heavy equipment manufacturing. The socket head design with 1/2" hex drive enables installation in confined spaces while accommodating high torque requirements. Engineered to withstand extreme mechanical stresses, these fasteners prevent joint failure in vibration-intensive environments, making them ideal for industrial applications requiring long-term reliability and minimal maintenance intervals.

Specification Summary & Compliance

This socket head cap screw features precision Class 3A thread fit with 5/8"-18 UNRF fine thread spacing and right-hand thread direction. Manufactured to ASTM A574 specifications, the fastener delivers consistent dimensional accuracy and mechanical properties. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use across global industrial markets. With a minimum thread length of 1 3/4" on a 6" partially threaded rod, this high-performance fastener meets the stringent requirements of professional engineering applications.