S-8077A839 1/4"-20 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 316 stainless steel construction, ideal for harsh industrial environments and chemical exposure
• Exceptional mechanical strength delivering 70,000 psi tensile and 35,000 psi shear strength for reliable performance under heavy loads
• Precision Class 3A thread fit ensures secure, vibration-resistant fastening with minimal backlash in critical assemblies
• Enhanced durability with black oxide finish providing added wear resistance and reduced light reflection
• Optimized installation control through knurled head texture and 5/32" hex drive for secure tool grip and torque transmission
• Accurate component alignment with consistent 7/16" shoulder length maintaining precise part spacing and rotation prevention
• Regulatory compliance assurance meeting ASME B18.3 specifications and environmental standards including RoHS 3 and REACH

Professional Applications & Engineering Value

Engineered for demanding industrial applications, this 316 stainless steel shoulder screw solves critical alignment and corrosion challenges in machinery assembly. The black oxide finish enhances surface durability while reducing galling in high-cycle operations. With 1/4"-20 UNC coarse threads and Class 3A fit, it maintains precise tolerances in vibrating environments where thread loosening compromises safety. The 7/16" shoulder length provides consistent bearing surfaces for rotating components in conveyor systems, robotic arms, and precision instruments. Rockwell B79 hardness ensures deformation resistance under lateral loads, making it ideal for pivot points, gear assemblies, and fixturing applications requiring repeated disassembly.

Specification Summary & Compliance

This shoulder screw maintains precision dimensional control with Class 3A thread fit per ASME B18.3 specifications. Critical shoulder dimensions include 5/16" diameter with -0.004" to -0.002" tolerance and 7/16" length with -0.005" to +0.005" tolerance. Manufacturing complies with ASME B18.3 standards for socket head shoulder screws, while material composition and finishing processes adhere to RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations.