S-91253A718 1/2"-13 x 1 3/4" 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 high-stress industrial environments, reducing the risk of fastener failure.
• Class 3A thread fit provides tighter tolerances for superior engagement and vibration resistance in critical assemblies.
• Black-oxide coating on alloy steel offers enhanced corrosion resistance, extending service life in harsh conditions.
• Fully threaded design allows for maximum grip and adjustability across the entire length, simplifying installation in varied material thicknesses.
• 82° countersink angle and flat head profile enable flush mounting for a clean, aerodynamic finish in precision applications.
• Hex drive (5/16") facilitates easy installation and removal with standard tools, minimizing assembly time and labor costs.
• Compliance with ASME B18.3 and ASTM F835 guarantees consistent quality and interoperability in regulated industries.

Professional Applications & Engineering Value

Engineered for heavy-duty industrial applications, these 1/2"-13 UNC flat head screws address common challenges like vibration loosening and corrosion in machinery, construction, and automotive sectors. The black-oxide alloy steel construction, combined with a Rockwell C39 hardness, ensures durability under repetitive stress, while the coarse thread and Class 3A fit enhance grip in metals and composites. Ideal for assemblies requiring flush mounting with an 82° countersink, they provide a secure, low-profile fastening solution that maintains integrity in demanding environments, reducing maintenance needs and downtime.

Specification Summary & Compliance

This screw features a 1/2"-13 UNC thread with Class 3A precision fit and coarse spacing for optimal performance. It meets ASME B18.3 and ASTM F835 specifications, ensuring dimensional accuracy and reliability. Additionally, it is RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, supporting environmental and safety standards in global supply chains.