S-91385A581 5/16"-18 x 3/4" 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
- Permanent vibration resistance through nylon patch thread locking that maintains secure fastening in high-stress environments
- Superior corrosion protection with black-oxide coating on alloy steel for extended service life in harsh conditions
- Precise thread engagement with Class 3A fit ensuring reliable assembly and reduced risk of cross-threading
- Wide temperature tolerance from -50°F to 250°F for stable performance across industrial applications
- High-strength construction with Rockwell C45 hardness providing excellent resistance to wear and deformation
- Secure cup point design creating positive locking action on shaft components without damaging surfaces
- Industry-standard compliance meeting ASME B18.3 specifications for consistent quality and interchangeability
Professional Applications & Engineering Value
This 5/16"-18 UNC set screw with nylon patch thread locker addresses critical vibration-induced loosening in industrial machinery, automotive components, and precision equipment. The black-oxide alloy steel construction provides essential corrosion resistance while maintaining Rockwell C45 hardness for durable performance under mechanical stress. Engineered with coarse thread spacing and Class 3A thread fit, this headless set screw ensures precise alignment and reliable fastening in pulley systems, gear assemblies, and coupling applications where space constraints demand compact hex drive solutions. The cup point design delivers superior biting action without compromising shaft integrity, making it ideal for permanent positioning applications requiring repeated adjustment cycles.
Specification Summary & Compliance
This set screw features 5/16"-18 UNC coarse threads with Class 3A precision tolerance and 3/4" length. Manufactured to ASME B18.3 specifications (ASTM F912) with 5/32" hex drive configuration. Fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental standards, ensuring safe use across regulated industries. The nylon patch thread locker maintains effectiveness across the specified temperature range of -50°F to 250°F.
