S-91259A444 1/2"-13 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 minimum shear strength for reliable performance in demanding applications
• Superior corrosion resistance through black oxide finish that protects against rust and extends service life in harsh environments
• Precision thread engagement with Class 3A thread fit ensuring secure fastening and vibration resistance in critical assemblies
• Enhanced grip and torque application featuring knurled head texture and 5/16" hex drive for secure tool engagement during installation
• Accurate component alignment with precisely machined shoulder diameter and length maintaining proper spacing in mechanical assemblies
• Industry-standard compliance meeting ASME B18.3 specifications and manufactured from ASTM A574 alloy steel for guaranteed quality
• Environmental responsibility with RoHS 3 and REACH compliance for safe use across various industrial sectors

Professional Applications & Engineering Value

This alloy steel shoulder screw delivers exceptional engineering value in precision mechanical systems where alignment accuracy and structural integrity are paramount. The 1/2"-13 UNC coarse thread configuration with Class 3A thread fit provides superior engagement in metal-to-metal applications, resisting loosening under vibration while the 2 1/8" shoulder length ensures precise component spacing in rotating assemblies, pivoting mechanisms, and bearing mounts. The black oxide finish offers reliable corrosion protection in industrial environments, while the knurled socket head with 5/16" hex drive prevents tool slippage during high-torque installation. Engineered to ASME B18.3 standards from ASTM A574 alloy steel, this shoulder screw maintains dimensional stability under heavy loads, making it ideal for machinery, automotive, and manufacturing equipment where failure is not an option.

Specification Summary & Compliance

This precision shoulder screw features 1/2"-13 UNC coarse threads with Class 3A thread fit for superior engagement, combined with precise shoulder dimensions (5/8" diameter with -0.004" to -0.002" tolerance and 2 1/8" length with -0.005" to 0.005" tolerance). Manufactured from high-strength alloy steel with Rockwell C32 hardness, the screw meets ASME B18.3 specifications and is produced from ASTM A574 material. Compliance includes RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring suitability for global industrial applications.