S-91259A370 1 1/8"-7 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Exceptional load-bearing capacity with 140,000 psi tensile strength and 84,000 psi minimum shear strength for reliable performance in demanding applications
• Precise shoulder alignment with controlled diameter tolerance (-0.004" to -0.002") ensuring accurate component positioning and reduced assembly time
• Superior corrosion resistance through black oxide finish that extends service life in harsh industrial environments
• Secure installation and removal with knurled socket head and 7/8" hex drive preventing tool slippage during high-torque applications
• Consistent thread engagement with Class 3A UNC coarse threads providing tighter tolerances for vibration-resistant assemblies
• Enhanced durability from Rockwell C32 hardened alloy steel construction that withstands repeated stress cycles
• Regulatory compliance assurance meeting ASME B18.3 specifications and environmental standards (RoHS 3, REACH) for global industrial use

Professional Applications & Engineering Value

This alloy steel shoulder screw delivers critical engineering solutions where precision alignment and high-strength fastening are paramount. The 1 1/2" shoulder diameter with tight tolerances provides accurate bearing surfaces for rotating components in machinery, while the 4" shoulder length maintains proper spacing in assemblies. The black oxide finish significantly enhances corrosion resistance in industrial environments where moisture and chemicals are present. With UNC coarse threads and Class 3A fit, this fastener ensures secure engagement in high-vibration applications such as heavy equipment, automotive fixtures, and manufacturing jigs. The knurled socket head design prevents cam-out during installation, reducing tool damage and improving worker safety in high-torque scenarios.

Specification Summary & Compliance

This shoulder screw maintains Class 3A thread fit per UNC standards with precise shoulder diameter tolerance (-0.004" to -0.002") and shoulder length tolerance (-0.005" to 0.005"). Manufacturing complies with ASME B18.3 specifications for dimensional consistency and performance reliability. The product meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental compliance standards, ensuring suitability for regulated industries and international markets.