S-91205A730 5/8"-11 x 1 3/4" ASME B18.3, ASTM A574 Alloy Steel Thread-Locking Socket Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 170,000 psi ensures reliable performance in high-stress applications, preventing fastener failure.
• Nylon patch thread locker provides secure, vibration-resistant locking from -70° to 250°F, maintaining clamp load in dynamic environments.
• Black-oxide finish on alloy steel offers superior corrosion resistance and a durable, non-galling surface for extended service life.
• Class 3A thread fit guarantees precise, tight-tolerance engagement for leak-proof and secure connections in critical assemblies.
• 1/2" hex drive and standard socket head allow for high-torque installation with common tools, reducing assembly time and effort.
• Coarse UNC thread enables quick assembly and disassembly, ideal for maintenance and heavy machinery applications.
• Full compliance with ASME B18.3 and ASTM A574 ensures consistent quality, dimensional accuracy, and interchangeability.

Professional Applications & Engineering Value

This black-oxide alloy steel socket head cap screw is engineered to address common industrial challenges such as vibration-induced loosening and high-load fatigue. The nylon patch thread locker embedded in the 5/8"-11 UNC coarse thread creates a permanent locking force, eliminating the need for secondary locking devices in machinery, automotive, and construction equipment. Its Rockwell C37 hardness and 170,000 psi tensile strength provide resilience against shock and tensile stresses, making it suitable for heavy-duty fastening in structural frames, hydraulic systems, and assembly jigs. The combination of alloy steel material and black-oxide surface treatment ensures durability in harsh environments, reducing maintenance frequency and downtime.

Specification Summary & Compliance

This screw features a Class 3A thread fit for precision engagement, with UNC coarse threads and a fully threaded 1 3/4" length. It conforms to ASME B18.3 and ASTM A574 specifications for dimensional and mechanical integrity. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring it is free from hazardous substances and safe for use in regulated industries.