S-91273A164 1/4"-28 Shoulder Screws

Key Features & Benefits at a Glance

• Exceptional corrosion resistance with 18-8 Stainless Steel construction, ideal for harsh industrial environments and extended service life.
• Superior strength and reliability offering a high 70,000 psi tensile strength and 35,000 psi shear strength for demanding applications.
• Precise and secure locating provided by the 1/4" diameter shoulder with controlled tolerances, ensuring accurate component alignment.
• Easy installation and high-torque capability with the hex socket drive and knurled head, preventing tool slippage and speeding up assembly.
• Fine-thread engagement with the 1/4"-28 UNF Class 2A thread, delivering superior vibration resistance and a tighter seal.
• Guaranteed material integrity with a Rockwell B55 hardness, balancing durability with necessary machinability.
• Compliance with global environmental standards including RoHS 3 and REACH, ensuring responsible and unrestricted use in various markets.

Professional Applications & Engineering Value

This stainless steel shoulder screw is engineered to address critical challenges in precision assembly. The unthreaded shoulder acts as a pivot, bearing surface, or axle, preventing wear on connected components and maintaining precise alignment in machinery, automotive systems, and electronic enclosures. Made from 18-8 Stainless Steel, it resists corrosion from coolants, weather, and chemicals, significantly increasing the lifespan of the assembly. The UNF fine thread provides more threads per inch compared to a coarse thread, resulting in a stronger joint that is less prone to loosening under vibration. Combined with the hex socket drive and knurled head for secure, high-torque installation, this fastener delivers reliable performance in demanding industrial fastening applications where precision and durability are non-negotiable.

Specification Summary & Compliance

This shoulder screw features a 1/4"-28 UNF thread with a Class 2A fit for consistent, free-spinning assembly. The shoulder diameter is 1/4" with a tolerance of -0.004" to -0.002", and the shoulder length is 3/8" with a tolerance of -0.005" to 0.005" for precise locating. Manufactured from 18-8 Stainless Steel, it meets the mechanical properties of 70,000 psi tensile strength and Rockwell B55 hardness. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations.