S-91253A291 1/4"-20 x 1 1/8" 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.
• Class 3A thread fit provides superior precision and tighter tolerances for secure, vibration-resistant assemblies.
• Black-oxide finish on alloy steel offers enhanced corrosion resistance and a durable, professional appearance.
• 82° countersink angle and flat head design allows for a flush, low-profile installation, minimizing protrusion in assembled components.
• Hex drive (5/32") enables high-torque installation with common tools, speeding up assembly and reducing slippage.
• Fully threaded coarse (UNC) design ensures maximum grip and holding power across the entire length for stable connections.
• Compliance with ASTM F835, RoHS 3, and REACH guarantees adherence to rigorous industrial and environmental standards for safe, reliable use.

Professional Applications & Engineering Value

These 1/4"-20 UNC flat head screws are engineered to address common industrial challenges such as vibration loosening and material fatigue. The black-oxide alloy steel construction, combined with a Rockwell C39 hardness, provides excellent durability and resistance to wear in high-stress environments. The fully threaded coarse spacing and Class 3A fit ensure a tight, secure connection that maintains integrity under dynamic loads. Ideal for machinery, automotive assemblies, and structural frameworks, these hex drive screws offer easy installation with standard tools, reducing assembly time and improving overall efficiency in industrial applications.

Specification Summary & Compliance

This product features precise Class 3A thread fit per UNC standards, with a coarse thread spacing and right-hand threading. Dimensions include a 1/4"-20 thread size, 1 1/8" length, and 82° countersink angle. Manufacturing and material specifications comply with ASTM F835, ensuring consistent quality and performance. Additionally, the screws are RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, meeting environmental and safety regulations for industrial use.