S-91259A873 1/2"-13 ASME B18.3, ASTM A574 Shoulder Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with black oxide finish for extended service life in demanding industrial environments
• Precise component alignment with 4 3/4" shoulder length maintaining consistent positioning in assemblies
• High-strength construction from alloy steel with Rockwell C32 hardness for maximum durability under heavy loads
• Secure installation and removal with 5/16" hex drive and knurled head for superior grip and torque transmission
• Reliable thread engagement with Class 3A fit UNC coarse threads ensuring vibration resistance and secure fastening
• Industry-standard compatibility meeting ASME B18.3 and ASTM A574 specifications for consistent performance
• Environmental compliance with RoHS 3 and REACH regulations for safe use in regulated applications

Professional Applications & Engineering Value

This shoulder screw delivers exceptional engineering value in precision industrial applications where component alignment and rotational accuracy are critical. The alloy steel construction with black oxide finish provides superior corrosion resistance while maintaining dimensional stability under mechanical stress. The 4 3/4" shoulder length serves as a precise locating surface for bearings, gears, and rotating components, eliminating the need for additional spacers or alignment fixtures. The UNC coarse threads with Class 3A fit ensure rapid assembly and disassembly while maintaining vibration resistance in high-speed machinery. The combination of socket head design with knurled texture and 5/16" hex drive facilitates secure tool engagement in confined spaces, making it ideal for manufacturing equipment, automation systems, and precision mechanical assemblies requiring reliable positioning and rotational control.

Specification Summary & Compliance

This shoulder screw features precision 1/2"-13 UNC coarse threads with Class 3A fit for superior thread engagement and dimensional accuracy. The shoulder diameter maintains tight tolerance of -0.004" to -0.002" while shoulder length tolerance ranges from -0.005" to 0.005" ensuring consistent performance. Manufactured in compliance with ASME B18.3 specifications and ASTM A574 material standards, with full compliance to RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations for industrial use.