S-91205A101 4-40 x 1/8" 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
- Exceptional vibration resistance with nylon patch thread locker that maintains integrity from -70° to 250°F, preventing loosening in dynamic applications
- Superior strength-to-weight ratio from alloy steel construction with 170,000 PSI tensile strength for demanding mechanical assemblies
- Precise installation control through hex socket drive design that prevents cam-out and ensures proper torque application
- Enhanced corrosion protection with black-oxide coating that provides durable surface finish in industrial environments
- Reliable thread engagement with Class 3A thread fit ensuring consistent performance in precision assemblies
- Optimized for space-constrained applications with compact 1/8" length and standard socket head profile
- Broad compatibility with UNC coarse threading that simplifies installation and replacement in existing systems
Professional Applications & Engineering Value
These black-oxide alloy steel socket head cap screws deliver critical performance in vibration-prone environments where fastener integrity is paramount. The nylon patch locking element creates consistent interference fit along the 4-40 UNC threads, effectively resisting rotational forces in machinery, automotive subsystems, and electronic enclosures. Engineered with Rockwell C37 hardness and 170,000 PSI tensile strength, these fasteners maintain structural integrity under extreme loads while the hex socket drive enables precise installation in confined spaces. The black-oxide surface treatment provides corrosion resistance without compromising dimensional accuracy, making these socket head cap screws ideal for precision assemblies requiring repeated maintenance access.
Specification Summary & Compliance
Manufactured to ASME B18.3 specifications with Class 3A thread fit precision and UNC coarse thread spacing. Features right-hand threading and fully threaded design with 3/32" hex drive compatibility. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental standards. Material certification includes ASTM A574 alloy steel composition for consistent mechanical properties.
