S-91255A718 1/2"-13 x 1 3/4" ASTM F835 Steel Button Head Hex-Drive Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 120,000 psi ensures reliable performance under extreme mechanical loads, reducing failure risks in demanding applications.
• Class 3A thread fit provides superior precision and tighter tolerances for secure, vibration-resistant connections in critical assemblies.
• Black-oxide coating on alloy steel enhances corrosion resistance and durability, extending service life in harsh industrial environments.
• 5/16" hex drive design allows for high-torque installation with standard tools, improving efficiency and reducing assembly time.
• Fully threaded UNC coarse threads enable faster engagement and stronger holding power in a wide range of materials.
• Rockwell C39 hardness offers excellent wear resistance, maintaining thread integrity through repeated use and high-stress conditions.
• Rounded button head profile provides a low-profile, finished appearance while minimizing snagging and enhancing safety.

Professional Applications & Engineering Value

These 1/2"-13 UNC rounded head screws are engineered to address common industrial challenges such as joint loosening under vibration and corrosion in aggressive environments. The black-oxide alloy steel construction, combined with a Class 3A thread fit, ensures precise alignment and sustained clamp load in heavy machinery, structural frameworks, and automotive assemblies. The coarse thread design facilitates quick installation in softer materials or where rapid disassembly is required, while the hex drive accommodates high torque applications without stripping. Ideal for industrial screws used in manufacturing, construction, and equipment maintenance, these fasteners deliver consistent performance where reliability and compliance with stringent standards are paramount.

Specification Summary & Compliance

This product adheres to Class 3A thread fit tolerances as per UNC standards, ensuring dimensional accuracy and interchangeability. Manufacturing and material specifications comply with ASME B18.3 and ASTM F835 for consistent quality and performance. Additionally, these screws are RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, meeting environmental and safety regulations for use in various global markets.