S-91259A801 3/8"-16 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
• Precision alignment and smooth rotation thanks to the 8" shoulder with tight diameter tolerance for consistent bearing surfaces
• Superior corrosion resistance through black oxide finish that protects against rust in demanding industrial environments
• Secure installation and removal with hex socket drive and knurled head providing excellent grip and torque transmission
• Reliable thread engagement with Class 3A thread fit ensuring precise, vibration-resistant fastening in machinery assemblies
• Enhanced durability from alloy steel construction with Rockwell C32 hardness for long service life under repeated loads
• Regulatory compliance assurance meeting ASME B18.3 specifications and environmental standards including RoHS 3 and REACH

Professional Applications & Engineering Value

This 3/8"-16 UNC shoulder screw delivers critical engineering value in precision machinery and industrial equipment where alignment accuracy and rotational stability are paramount. The 8" shoulder length with controlled diameter tolerance provides a consistent bearing surface for gears, pulleys, and rotating components, eliminating misalignment issues that cause premature wear. The alloy steel construction with black oxide finish ensures corrosion resistance in harsh environments while maintaining the 140,000 psi tensile strength needed for high-load applications. The hex socket head with knurled texture enables secure installation in confined spaces, making these shoulder screws ideal for precision assemblies in automation equipment, manufacturing machinery, and motion control systems where reliability and dimensional accuracy are non-negotiable.

Specification Summary & Compliance

This shoulder screw features 3/8"-16 UNC coarse threads with Class 3A thread fit for precision engagement, an 8" shoulder length with diameter tolerance of -0.004" to -0.002", and shoulder length tolerance of -0.005" to 0.005". Manufactured to ASME B18.3 specifications using ASTM A574 alloy steel, the fastener demonstrates full compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring suitability for global industrial applications with strict material restrictions.