S-91385A172 1/2"-13 x 3" ASME B18.3, ASTM F912 Set Screws

Key Features & Benefits at a Glance

• Superior Vibration Resistance: Nylon patch thread locker maintains secure fastening even under extreme vibration, preventing loosening in demanding applications.
• Exceptional Durability & Strength: Made from black-oxide alloy steel with a Rockwell C45 hardness for high tensile strength and long-term reliability in heavy-duty use.
• Wide Temperature Tolerance: The nylon patch remains effective from -50°F to 250°F, ensuring reliable performance in both high-heat and cryogenic environments.
• Precise & Secure Fastening: Class 3A thread fit provides tighter tolerances than standard fits, offering superior accuracy and a more secure connection.
• Enhanced Corrosion Resistance: The black-oxide finish provides a protective layer, increasing the screw's resistance to rust and corrosion in harsh industrial settings.
• Easy Installation & Removal: The 1/4" hex drive allows for high-torque application with standard tools, while the headless, cup tip design provides positive seating without protruding.
• Proven Industry Compliance: Manufactured to meet ASME B18.3 and ASTM F912 specifications, ensuring consistent quality and performance you can trust.

Professional Applications & Engineering Value

This black-oxide alloy steel set screw is engineered to solve critical challenges in industrial assembly and machinery. The headless design with a cup tip ensures a flush finish and positive grip, ideal for securing collars, gears, and pulleys on shafts without creating protrusions. The 1/2"-13 UNC coarse thread facilitates faster installation and provides strong holding power. The inclusion of a nylon patch thread locker directly addresses the common industrial problem of fastener loosening due to vibration and thermal cycling, making it a reliable choice for automotive, aerospace, and heavy machinery applications where high-temperature resistance and unwavering clamp force are non-negotiable.

Specification Summary & Compliance

This set screw features a precise Class 3A thread fit per the UNC standard, ensuring excellent dimensional accuracy. It is manufactured in compliance with ASME B18.3 and ASTM F912 specifications. The product is also verified to be RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, confirming it is free of hazardous substances and suitable for use in regulated markets.