S-91381A681 4-40 x 3/16" 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
- Secure Component Positioning – Class 3A thread fit ensures tight, vibration-resistant connections for reliable industrial assemblies
- Enhanced Surface Protection – Black-oxide coating on alloy steel provides corrosion resistance and extended service life
- Mar-Free Fastening – Soft brass tip prevents damage to precision components while maintaining strong clamping force
- High-Strength Construction – Rockwell C28 hardness delivers excellent durability under mechanical stress
- Space-Saving Design – Headless configuration allows installation in confined spaces where standard screws won't fit
- Quick Installation – Hex drive (0.050") enables efficient torque application with standard hex tools
- Industry Compliance – Meets ASME B18.3 specifications and environmental regulations for global manufacturing applications
Professional Applications & Engineering Value
This 4-40 UNC thread set screw with Class 3A fit addresses critical challenges in precision assembly operations. The black-oxide alloy steel construction provides superior corrosion resistance while maintaining Rockwell C28 hardness for demanding applications. The innovative soft brass tip prevents marring and damage to sensitive shaft surfaces, making it ideal for positioning collars, gears, and pulleys on precision machinery. The coarse thread spacing ensures rapid installation and superior holding power in right-hand thread applications. Engineered for industrial set screws requirements, this headless set screw delivers reliable performance in automation equipment, electronic enclosures, and mechanical drive systems where space constraints and component protection are paramount.
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 with 3/16" length and hex drive 0.050" configuration. Fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use in global manufacturing applications.
