S-91205A105 4-40 x 1/4" ASME B18.3, ASTM A574 Alloy Steel Thread-Locking Socket Head Screws
Alloy Steel Thread-Locking Socket Head 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 permanent nylon patch thread locker that prevents loosening under dynamic loads
- Exceptional strength-to-weight ratio from alloy steel construction with 170,000 psi tensile strength for demanding applications
- Reliable performance across extreme temperatures with thread locker effective from -70° to 250°F
- Precise installation and removal through standard hex socket drive requiring only 3/32" hex key
- Enhanced corrosion protection from black-oxide surface treatment extending service life
- Secure fastening in high-vibration environments with Class 3A thread fit ensuring tight tolerances
- Industry-standard compatibility with UNC coarse threads for easy replacement and interchangeability
Professional Applications & Engineering Value
These black-oxide alloy steel socket head cap screws deliver critical reliability in applications where vibration resistance and precise clamping force are paramount. The permanent nylon patch thread locker embedded in the 4-40 UNC coarse threads creates a chemical-mechanical bond that maintains fastener integrity in machinery, automotive assemblies, and electronic enclosures subject to constant motion or thermal cycling. The Rockwell C37 hardness rating combined with 170,000 psi tensile strength ensures these fully threaded fasteners withstand both static and dynamic loading conditions without compromising the Class 3A thread fit precision. The hex drive socket design allows for high torque application in confined spaces, making them ideal for precision equipment maintenance and manufacturing applications requiring repeated disassembly and reassembly.
Specification Summary & Compliance
Manufactured to ASME B18.3 specifications with material compliance to ASTM A574 standards. Features Class 3A thread fit for superior dimensional accuracy in 4-40 UNC coarse thread configuration. Fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations. The 1/4" length and fully threaded design ensures consistent engagement depth across applications.
