S-91266A544 1/4"-20 x 1 1/4" ASTM F835 Alloy Steel Thread-Locking Hex Drive Flat Head Screws
Alloy Steel Thread-Locking Hex Drive Flat 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
- Permanent vibration resistance with nylon patch locking that maintains integrity across a wide temperature range from -65° to 250°F
- Exceptional durability and corrosion protection through black-oxide alloy steel construction with Rockwell C39 hardness
- Maximum load-bearing capacity with 130,000 psi tensile strength for demanding industrial applications
- Superior thread engagement and precision fit through Class 3A UNC coarse threading that prevents cross-threading
- Secure flush mounting with standard 82° flat head profile and hex drive for reliable countersinking
- Full-length fastening capability with complete threading along the entire 1-1/4" length for uniform load distribution
- Regulatory compliance assurance meeting ASTM F835, RoHS 3, and REACH standards for global industrial use
Professional Applications & Engineering Value
These black-oxide alloy steel flat head screws with nylon patch locking technology deliver critical vibration resistance in demanding environments where thermal cycling and mechanical stress compromise conventional fasteners. The Class 3A UNC coarse threading ensures rapid installation with superior thread engagement, while the hex drive provides high torque transmission without cam-out. Engineered for machinery, industrial equipment, and automotive assemblies, these fully threaded screws maintain clamping force integrity across extreme temperature fluctuations from -65° to 250°F. The combination of 130,000 psi tensile strength and permanent locking mechanism addresses common failure points in vibration-prone applications, delivering reliable performance where fastener security is non-negotiable.
Specification Summary & Compliance
Manufactured to precise dimensional standards with Class 3A thread fit and UNC coarse threading (1/4"-20), these flat head screws feature a standard 82° countersink angle and hex drive compatibility. The product meets ASTM F835 specifications for mechanical properties and is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring suitability for global industrial markets and restricted substance requirements.
