S-91266A718 1/2"-13 x 1 3/4" ASTM F835 Alloy Steel Thread-Locking Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Superior vibration resistance with nylon patch thread locking that maintains secure fastening from -65° to 250°F
• Exceptional tensile strength of 130,000 psi ensures reliable performance in high-stress applications
• Precise Class 3A thread fit provides consistent engagement and reduces the risk of cross-threading
• Corrosion-resistant black-oxide finish on alloy steel extends service life in demanding environments
• Optimized hex drive design (5/16") allows for high torque application and prevents tool slippage
• Full threading capability ensures maximum grip length and uniform load distribution
• Industry compliance assurance with ASTM F835 standards and environmental regulations (RoHS 3/REACH)

Professional Applications & Engineering Value

These 1/2"-13 UNC flat head screws deliver critical engineering solutions where vibration resistance and thermal stability are paramount. The black-oxide alloy steel construction combined with Rockwell C39 hardness provides exceptional durability against wear and environmental factors. The nylon patch locking technology effectively prevents loosening in machinery subjected to constant motion or thermal cycling from -65° to 250°F. The coarse UNC threading and 82° countersink angle ensure rapid installation and flush mounting in structural assemblies, automotive components, and heavy equipment where high-strength fasteners must maintain integrity under extreme operational stresses.

Specification Summary & Compliance

Manufactured to precise Class 3A thread fit tolerances with UNC coarse threading (1/2"-13) and full threading along the 1 3/4" length. These flat head screws conform to ASTM F835 manufacturing specifications and demonstrate compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring they meet rigorous industrial standards for quality and safety.