S-91385A171 1/2"-13 x 2 1/2" ASME B18.3, ASTM F912 Set Screws
Set Screws
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Basic Information
Head Parameters
Dimensions
Thread Parameters
Tip & Drive Parameters
Material & Strength
Temperature & Environment
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Key Features & Benefits at a Glance
- Superior vibration resistance with nylon patch thread locker that maintains integrity from -50°F to 250°F
- Exceptional durability from black-oxide alloy steel construction with Rockwell C45 hardness rating
- Precise thread engagement through Class 3A fit UNC coarse threads for reliable fastening in high-stress applications
- Easy installation and removal with 1/4" hex drive design in headless configuration for space-constrained environments
- Enhanced grip and positioning with cup tip design that minimizes component surface damage
- Industry compliance assurance meeting ASME B18.3 specifications and global environmental standards
- Optimized for heavy-duty use with 2-1/2" length providing substantial engagement depth for critical assemblies
Professional Applications & Engineering Value
This black-oxide alloy steel set screw delivers critical performance in demanding industrial environments where vibration resistance and positional stability are paramount. The nylon patch thread locker embedded in the UNC coarse threads creates permanent fastening that withstands extreme temperature fluctuations from -50°F to 250°F, eliminating the need for secondary locking mechanisms. The headless design with hex drive enables installation in confined spaces while maintaining high torque capability. Engineers specify this Class 3A thread fit set screw for machinery components, power transmission systems, and precision equipment where vibration-induced loosening would compromise safety or operational integrity. The cup tip configuration provides concentrated contact pressure without damaging shaft surfaces, making it ideal for permanent positioning of gears, pulleys, and collars on rotating equipment.
Specification Summary & Compliance
This industrial-grade set screw features 1/2"-13 UNC coarse threads manufactured to Class 3A tolerance for precise fit and maximum strength. The fastener conforms to ASME B18.3 specifications (ASTM F912) and carries full compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations. The black-oxide surface treatment on alloy steel provides corrosion resistance while maintaining the Rockwell C45 hardness rating essential for repeated use in high-stress applications.
