S-91273A306 5/16"-18 Shoulder Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 stainless steel construction, ideal for harsh industrial environments and extended service life.
• Precise component alignment and spacing ensured by the consistent 1/2" shoulder diameter and length, reducing assembly errors.
• High-strength performance with a tensile strength of 70,000 psi and a minimum shear strength of 35,000 psi for reliable load-bearing applications.
• Secure and tamper-resistant installation facilitated by the internal hex socket drive and knurled head for improved grip during tightening.
• Broad compatibility with the standardized 5/16"-18 UNC coarse thread and Class 2A fit, ensuring easy interchangeability.
• Enhanced durability from a Rockwell B55 hardness rating, providing excellent resistance to wear and deformation.
• Compliance with global environmental standards including RoHS 3 and REACH, making it suitable for regulated industries.

Professional Applications & Engineering Value

This 5/16"-18 UNC shoulder screw is engineered to address critical alignment and pivot point requirements in precision applications. The 18-8 stainless steel material offers excellent resistance to corrosion and oxidation, which is vital for machinery operating in demanding conditions like automation systems, conveyor assemblies, and medical equipment. The 1/2" shoulder length acts as a precise datum for locating parts, eliminating misalignment and reducing stress concentrations. Combined with the hex socket head and knurled texture, it allows for high-torque installation without slippage, ensuring consistent clamping force and operational reliability in industrial fasteners assemblies.

Specification Summary & Compliance

This shoulder screw adheres to UNC coarse thread standards with a Class 2A thread fit for consistent engagement. The shoulder diameter is maintained at 5/16" with a tight tolerance of -0.004" to -0.002", and the shoulder length is 1/2" with a tolerance of -0.005" to 0.005" for precise dimensional control. Manufacturing and material specifications ensure compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its suitability for use in environmentally conscious and regulated industrial sectors.