S-91381A670 4-40 x 1/8" ASME B18.3 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 corrosion resistance with black-oxide coating on alloy steel, extending service life in demanding environments
- Precise Class 3A thread fit ensures reliable engagement and vibration resistance in critical assemblies
- Non-marring brass tip protects sensitive surfaces while maintaining secure clamping force
- High-strength construction with Rockwell C28 hardness provides excellent durability under load
- Compact headless design allows flush installation where space is constrained
- Standardized UNC coarse threads enable quick installation and compatibility with common components
- 0.050" hex drive offers positive torque transmission during installation and removal
Professional Applications & Engineering Value
This 4-40 UNC set screw delivers exceptional engineering value for precision positioning and clamping applications. The black-oxide alloy steel construction provides enhanced corrosion protection in industrial environments, while the Class 3A thread fit ensures consistent performance in high-vibration machinery. The integrated brass tip prevents damage to shafts and precision components, making it ideal for securing gears, pulleys, and collars without compromising surface integrity. With its headless design and coarse thread spacing, this fastener enables rapid installation in confined spaces while maintaining reliable holding power. The combination of Rockwell C28 hardness and standardized UNC threads makes it suitable for automated assembly systems and maintenance applications across manufacturing, automotive, and equipment manufacturing sectors.
Specification Summary & Compliance
This precision fastener features 4-40 UNC coarse threads with Class 3A thread fit for superior dimensional accuracy. Manufactured to ASME B18.3 specifications, the set screw maintains strict quality standards throughout production. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use across global markets. Additional specifications include right-hand thread direction, 1/8" length, and 0.050" hex drive size for consistent performance in industrial applications.
