S-91263A603 1/2"-13 x 1 1/4" ASTM F835 Alloy Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 130,000 psi ensures reliable performance in demanding applications, reducing the risk of fastener failure
• Zinc-plated alloy steel construction provides superior corrosion resistance, extending service life in harsh industrial environments
• Class 3A thread fit delivers precise, tight-tolerance engagement for secure fastening and vibration resistance
• 82° countersink angle with standard flat head profile enables flush mounting for clean, professional finishes and improved safety
• 5/16" hex drive design allows for high-torque installation with common tools, speeding up assembly processes
• Rockwell C39 hardness rating maintains thread integrity and drive durability through repeated use and high-stress conditions
• Full threading along the 1-1/4" length provides maximum grip and adjustment flexibility in various material thicknesses

Professional Applications & Engineering Value

These 1/2"-13 UNC flat head hex drive screws are engineered to address critical challenges in industrial assembly and machinery applications. The zinc-plated alloy steel construction combined with coarse UNC threading provides exceptional resistance to loosening under vibration, making them ideal for heavy equipment, structural frameworks, and automotive components. The 82° countersink angle ensures seamless flush mounting in precision applications where protruding fasteners could interfere with moving parts or create safety hazards. With fully threaded design and Class 3A fit, these screws deliver maximum clamping force and consistent performance across varying material densities, solving common issues of strip-out and insufficient holding power in demanding environments.

Specification Summary & Compliance

This flat head screw features precise Class 3A thread fit with 1/2"-13 UNC coarse threading and right-hand thread direction. Manufactured to meet ASTM F835 specifications for mechanical properties and dimensional accuracy. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use across global industrial markets.