S-91385A108 4-40 x 3/8" 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
- Vibration-resistant locking with nylon patch thread locker that maintains secure fastening from -50°F to 250°F
- Exceptional durability through Rockwell C45 hardness and black-oxide coated alloy steel construction
- Precise thread engagement with Class 3A thread fit ensuring reliable performance in demanding applications
- Easy installation and removal via hex drive design requiring only 0.050" drive tool
- Maximum holding power through cup point design that creates permanent seating in mating materials
- Industry-standard compatibility with UNC coarse thread spacing for broad application versatility
- Environmental compliance meeting RoHS 3 and REACH regulations for global manufacturing use
Professional Applications & Engineering Value
This 4-40 UNC thread set screw delivers critical vibration resistance in industrial assemblies where loosening under dynamic loads compromises safety and performance. The black-oxide alloy steel construction provides corrosion resistance while maintaining Rockwell C45 hardness for repeated use in high-stress environments. The nylon patch locking element eliminates the need for separate locking components, reducing assembly time and parts inventory. Engineered with Class 3A thread fit precision, this headless set screw ensures flush mounting in machinery, automotive components, and precision instruments where space constraints demand reliable fastening solutions that withstand temperature fluctuations from -50°F to 250°F.
Specification Summary & Compliance
Manufactured to ASME B18.3 specifications with Class 3A thread fit tolerance for superior dimensional accuracy. Features UNC coarse thread spacing with right-hand thread direction and 3/8" length. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use in global industrial applications. The black-oxide surface treatment on alloy steel substrate provides enhanced corrosion protection while maintaining the mechanical properties required for demanding fastening applications.
