S-91259A482 5/16"-18 ASME B18.3, ASTM A574 Shoulder Screws

Key Features & Benefits at a Glance

• Exceptional load-bearing capacity with 140,000 psi tensile strength for reliable performance in high-stress applications
• Superior corrosion resistance provided by black oxide finish, extending service life in demanding environments
• Precision thread engagement with Class 3A fit and UNC coarse threads ensuring secure fastening and vibration resistance
• Enhanced installation control through hex drive design and knurled head for improved grip during assembly
• Accurate shoulder positioning with tight diameter tolerance (-0.004" to -0.002") for precise component alignment
• Long-term durability from Rockwell C32 hardened alloy steel maintaining structural integrity under repeated use
• Regulatory compliance assurance meeting ASME B18.3, ASTM A574, RoHS 3, and REACH standards for quality and safety

Professional Applications & Engineering Value

This alloy steel shoulder screw delivers critical engineering solutions across industrial applications where precision alignment and high strength are paramount. The black oxide finish provides essential corrosion protection for machinery components exposed to harsh operating conditions, while the 5/16"-18 UNC coarse thread with Class 3A fit ensures rapid assembly and superior vibration resistance in automated equipment. The precisely machined shoulder with tight diameter tolerance facilitates accurate bearing and bushing alignment in rotating assemblies, reducing wear and maintenance requirements. Engineered to ASTM A574 specifications and ASME B18.3 standards, these shoulder screws offer reliable performance in precision instruments, industrial machinery, and motion control systems where dimensional accuracy and structural integrity are non-negotiable.

Specification Summary & Compliance

Manufactured to exacting standards with Class 3A thread fit and UNC coarse thread profile ensuring precise engagement. The shoulder diameter maintains tight tolerance of -0.004" to -0.002" for accurate component alignment. Compliant with ASME B18.3 dimensional specifications and ASTM A574 material requirements. Meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations for hazardous substance restrictions, ensuring safe use across global industrial markets.