S-97768A440 5/16"-18 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 stainless steel construction and black oxide finish, ideal for harsh industrial environments
• Precise alignment and spacing ensured by the 1/2" shoulder diameter with tight tolerance control for consistent assembly performance
• High load-bearing capability with 70,000 psi tensile strength and 35,000 psi shear strength for demanding mechanical applications
• Secure, slip-resistant installation thanks to the knurled socket head and hex drive design for reliable torque transmission
• Exceptional thread accuracy with Class 3A UNC coarse threads providing superior fit and vibration resistance
• Long-term durability supported by Rockwell B55 hardness, maintaining structural integrity under repeated stress
• Regulatory compliance assurance meeting ASME B18.3, RoHS 3, and REACH standards for global industrial use

Professional Applications & Engineering Value

This 5/16"-18 UNC shoulder screw is engineered to address critical alignment and load distribution challenges in precision assemblies. The 18-8 stainless steel base material, enhanced with a black oxide finish, provides excellent resistance to corrosion and wear in demanding environments such as machinery, automotive, and electronic enclosures. The 2" shoulder length and controlled diameter tolerances allow for exact component positioning, reducing misalignment and wear in rotating assemblies or pivot points. The knurled socket head ensures secure tool engagement during installation, minimizing slippage in high-torque applications. With its Class 3A thread fit and coarse thread spacing, it offers reliable fastening in vibrating systems, making it a trusted solution for OEMs and maintenance teams requiring repeatable performance and reduced downtime.

Specification Summary & Compliance

This shoulder screw features a 5/16"-18 UNC thread with Class 3A precision fit, ensuring tight tolerances for secure fastening. The shoulder diameter is maintained at 1/2" with a tolerance of -0.004" to -0.002", while the shoulder length is 2" with a tolerance of -0.005" to 0.005" for consistent dimensional accuracy. Manufactured in compliance with ASME B18.3 specifications, it also meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental standards, supporting safe and sustainable industrial applications.