S-91253A974 5/16"-18 x 1 3/8" ASTM F835 Alloy Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Exceptional corrosion resistance with black-oxide coating, ideal for harsh industrial environments
• Superior tensile strength (130,000 psi) ensures reliable performance under heavy loads
• Precise Class 3A thread fit provides secure, vibration-resistant connections
• Fully threaded design allows for maximum grip and adjustment flexibility
• 82° countersink angle enables flush mounting for clean, professional finishes
• Hex drive compatibility facilitates quick installation with standard tools
• Compliance with major standards including ASTM F835, RoHS 3, and REACH for guaranteed quality

Professional Applications & Engineering Value

These 5/16"-18 UNC flat head screws deliver critical performance advantages in demanding applications. The black-oxide alloy steel construction provides excellent durability against corrosion and wear, while the Rockwell C39 hardness ensures long-term reliability in high-stress environments. The coarse UNC thread design offers superior holding power in various materials, and the fully threaded configuration maximizes engagement depth. Perfect for machinery assembly, structural frameworks, and heavy equipment where vibration resistance and flush mounting are essential, these screws solve common industrial fastening challenges with precision engineering.

Specification Summary & Compliance

Manufactured to exacting standards with Class 3A thread fit for superior tolerance control and UNC coarse thread specifications. Complies with ASTM F835 manufacturing requirements, RoHS 3 (2015/863/EU) for hazardous substance restrictions, and REACH (EC 1907/2006) environmental regulations. The 82° countersink angle and fully threaded design ensure consistent performance across industrial applications.