S-91259A149 3/4"-10 ASME B18.3, ASTM A574 Shoulder Screws

Key Features & Benefits at a Glance

• Exceptional load-bearing capacity with 140,000 psi tensile strength and 84,000 psi shear strength for reliable performance in demanding applications
• Precision alignment and secure positioning thanks to the 1" shoulder diameter with tight tolerance control for consistent component mounting
• Superior corrosion resistance provided by the black oxide finish, extending service life in harsh industrial environments
• Secure installation and removal enabled by the knurled socket head and 1/2" hex drive, preventing tool slippage during torque application
• Reliable thread engagement with Class 3A UNC coarse threads ensuring vibration resistance and easy assembly in high-volume production
• Enhanced durability from Rockwell C32 hardness alloy steel construction, maintaining dimensional stability under repeated loads
• Regulatory compliance assurance meeting ASME B18.3 standards and environmental regulations 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" shoulder diameter with controlled tolerances provides exact component positioning in machinery, automation systems, and rotating assemblies, eliminating misalignment issues. The black oxide finish offers substantial corrosion protection for industrial environments exposed to moisture and chemicals. With 3/4"-10 UNC Class 3A threads and 140,000 psi tensile strength, this fastener maintains integrity under extreme vibrational loads and dynamic stresses common in manufacturing equipment, automotive jigs, and heavy machinery. The knurled socket head combined with the 1/2" hex drive ensures positive tool engagement during installation, reducing assembly time and preventing damage to critical components.

Specification Summary & Compliance

This shoulder screw maintains Class 3A thread fit per UNC standards with shoulder diameter tolerance of -0.004" to -0.002" and shoulder length tolerance of -0.005" to 0.005" for precision applications. Manufactured to ASME B18.3 specifications using ASTM A574 alloy steel, it delivers consistent mechanical properties and dimensional accuracy. The product is fully RoHS 3 (2015/863/EU) compliant and REACH (EC 1907/2006) compliant, meeting international environmental regulations for industrial fastener applications.