S-91273A178 5/16"-18 Shoulder Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 stainless steel construction, ideal for harsh environments and extended service life.
• Precise component alignment ensured by the 1-3/4" shoulder length with tight tolerances, reducing assembly errors and wear.
• High-strength fastening with 70,000 psi tensile strength and 35,000 psi minimum shear strength for demanding mechanical applications.
• Secure, high-torque installation via the 5/32" hex socket drive and knurled head, preventing tool slippage and ensuring reliable clamping force.
• Easy assembly and disassembly with a standard UNC coarse thread (Class 2A fit) and right-hand direction, speeding up maintenance and production.
• Enhanced durability from Rockwell B55 hardness, providing excellent resistance to deformation under load.
• Regulatory compliance and safety with RoHS 3 and REACH standards, ensuring environmental and workplace safety in global markets.

Professional Applications & Engineering Value

This 5/16"-18 UNC shoulder screw is engineered to address critical alignment and durability challenges in industrial settings. The 18-8 stainless steel material offers exceptional corrosion resistance, making it suitable for applications exposed to moisture, chemicals, or outdoor conditions, such as machinery, automotive assemblies, and conveyor systems. The 1-3/4" precision shoulder provides a stable bearing surface for rotating parts like pulleys, gears, and linkages, minimizing misalignment and reducing wear on components. Combined with a hex socket drive and coarse thread, it ensures quick, secure fastening even in high-vibration environments, enhancing operational efficiency and reducing downtime. Ideal for industrial fasteners in manufacturing and engineering, this screw delivers reliable performance where precision and strength are paramount.

Specification Summary & Compliance

This shoulder screw adheres to UNC coarse thread standards with a Class 2A thread fit for consistent engagement and ease of assembly. Key dimensions include a shoulder diameter of 5/16" with a tolerance of -0.004" to -0.002" and a shoulder length of 1-3/4" with a tolerance of -0.005" to 0.005", ensuring precise manufacturing. It complies with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its suitability for environmentally conscious and safe industrial use.