S-91266A580 5/16"-18 x 5/8" 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 thread locker that maintains secure fastening in high-stress environments
- Superior corrosion protection through black-oxide coating on alloy steel for extended service life in harsh conditions
- Exceptional mechanical strength with 130,000 psi tensile strength and Rockwell C39 hardness for heavy-duty applications
- Precise thread engagement with Class 3A fit ensuring reliable performance and reduced installation issues
- Wide temperature tolerance from -65° to 250°F for stable performance across diverse operating environments
- Optimal flush mounting with standard 82° countersink angle and flat head design for smooth surface finishing
- Enhanced installation efficiency through hex drive design providing secure tool engagement and torque transmission
Professional Applications & Engineering Value
Engineered for demanding industrial applications, these 5/16"-18 UNC flat head screws with nylon patch locking technology provide reliable vibration-resistant fastening solutions. The black-oxide alloy steel construction delivers exceptional durability against corrosion and wear, while the Class 3A thread fit ensures precise engagement in critical assemblies. Ideal for machinery, automotive, and heavy equipment applications where permanent thread locking is essential, these screws maintain integrity across temperature extremes from -65° to 250°F. The combination of 130,000 psi tensile strength and fully threaded design provides maximum holding power in structural applications, reducing maintenance requirements and enhancing operational safety.
Specification Summary & Compliance
Manufactured to exacting standards with Class 3A thread fit and UNC coarse threading for superior engagement. Fully compliant with ASTM F835 specifications for mechanical properties and performance. Meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use in industrial applications worldwide. Features precise dimensional control with 5/8" length, 0.313" thread diameter, and standard 82° countersink angle for consistent performance across production runs.
