S-91259A187 3/8"-16 ASME B18.3, ASTM A574 Shoulder Screws

Key Features & Benefits at a Glance

• Enhanced Durability - Alloy steel construction with Rockwell C32 hardness provides superior resistance to wear and deformation in demanding applications
• Precision Alignment - Class 3A thread fit and tight shoulder diameter tolerance (-0.004" to -0.002") ensure exact positioning and reduced assembly vibration
• Corrosion Protection - Black oxide finish offers reliable rust resistance while maintaining dimensional stability
• Secure Installation - Knurled socket head with hex drive provides excellent grip and prevents tool slippage during high-torque applications
• Industry Compliance - Meets ASME B18.3 specifications for consistent performance and interchangeability
• Environmental Safety - RoHS 3 and REACH compliant for use in regulated industries and international markets
• Optimized Strength - 6" shoulder length with minimal tolerance variation (-0.005" to 0.005") maintains structural integrity under heavy loads

Professional Applications & Engineering Value

This alloy steel shoulder screw delivers exceptional engineering value in precision machinery and heavy-duty assemblies. The 3/8"-16 UNC coarse thread with Class 3A fit ensures secure fastening in high-vibration environments, while the precisely machined 6" shoulder length provides accurate pivot points and bearing surfaces in rotating assemblies. The black oxide finish not only enhances corrosion resistance but also reduces galling during installation. Ideal for industrial equipment, automation systems, and machinery where socket head design with knurled texture allows for reliable tool engagement in confined spaces. This shoulder screw solves critical alignment challenges while maintaining structural integrity under continuous operational stress.

Specification Summary & Compliance

Manufactured to exacting standards with Class 3A thread fit and shoulder diameter tolerance of -0.004" to -0.002". Complies with ASME B18.3 specifications for dimensional consistency and performance reliability. Meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental compliance requirements. The UNC coarse thread pattern and precise shoulder dimensions ensure interchangeability and repeatable performance in industrial applications.