S-91266A592 5/16"-24 x 3/4" ASTM F835 Alloy Steel Thread-Locking Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Permanent vibration resistance with nylon patch thread locker that maintains secure fastening from -65° to 250°F
• Exceptional tensile strength of 130,000 PSI ensures reliable performance under heavy loads and stress
• Superior thread precision with Class 3A fit and UNF fine threading for secure, accurate engagement in critical applications
• Enhanced corrosion protection through black-oxide coating on alloy steel, extending service life in demanding environments
• Optimized drive efficiency with 3/16" hex drive providing maximum torque transfer and reduced cam-out risk
• Streamlined installation with standard 82° countersink angle allowing flush mounting in precision assemblies
• Full regulatory compliance meeting ASTM F835, RoHS 3, and REACH standards for global industrial use

Professional Applications & Engineering Value

This 5/16"-24 UNF nylon patch locking flat head screw addresses critical vibration-induced loosening in industrial equipment, machinery, and automotive assemblies. The permanent nylon patch thread locker creates a chemical bond that withstands extreme temperature fluctuations from -65° to 250°F, eliminating the need for secondary locking devices. Manufactured from black-oxide alloy steel with Rockwell C39 hardness, these flat head screws maintain integrity under continuous stress while the Class 3A thread fit ensures precise engagement in tapped holes. The 82° countersink angle and hex drive design facilitate rapid installation in tight spaces, making them ideal for production lines requiring both speed and reliability in industrial fastening applications.

Specification Summary & Compliance

This locking flat head screw features precision 5/16"-24 UNF fine threads with Class 3A thread fit for superior engagement accuracy. The fastener is fully threaded with right-hand direction and incorporates a nylon patch locking element for permanent vibration resistance. Manufacturing specifications conform to ASTM F835 standards, with full compliance to RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring suitability for global industrial applications requiring certified components.