S-91259A480 1/4"-20 ASME B18.3, ASTM A574 Shoulder Screws

Key Features & Benefits at a Glance

• Exceptional durability with alloy steel construction and black oxide finish providing reliable corrosion resistance for harsh industrial environments.
• Superior load-bearing capacity thanks to 140,000 psi tensile strength and Rockwell C32 hardness, ensuring long-term performance under stress.
• Precise alignment and smooth rotation enabled by the 2 1/8" shoulder with tight diameter tolerance for accurate component positioning.
• Easy installation and removal with the 5/32" hex drive and knurled head offering secure grip and high torque application.
• Reliable thread engagement through Class 3A UNC coarse threads, minimizing cross-threading and speeding up assembly processes.
• Broad compatibility with standard 1/4"-20 UNC threading, making it suitable for various machinery and equipment applications.
• Compliance with industry standards including ASME B18.3, RoHS 3, and REACH, ensuring safety and environmental responsibility.

Professional Applications & Engineering Value

This alloy steel shoulder screw is engineered to address critical challenges in industrial assembly, where precision and strength are paramount. The black oxide finish enhances corrosion resistance, extending service life in demanding conditions like manufacturing equipment and automotive systems. Its 1/4"-20 UNC coarse threads and Class 3A fit provide secure fastening with reduced risk of stripping, while the 2 1/8" shoulder length ensures accurate alignment for rotating parts, minimizing wear and maintenance. Ideal for applications requiring high tensile strength and durability, this screw supports efficient B2B procurement by meeting rigorous performance and regulatory demands.

Specification Summary & Compliance

This shoulder screw adheres to precise dimensional standards, including Class 3A thread fit for superior accuracy and UNC coarse threads with a 1/4"-20 size. Manufacturing follows ASME B18.3 specifications, with shoulder diameter tolerance of -0.004" to -0.002" and length tolerance of -0.005" to 0.005". It is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006), ensuring environmental safety and regulatory adherence for industrial use.