S-91253A348 3/8"-16 x 1 3/8" ASTM F835 Alloy Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Exceptional Tensile Strength: With 130,000 psi tensile strength, these screws provide reliable fastening under high-stress conditions, reducing the risk of joint failure in demanding applications.
• Superior Corrosion Resistance: The black-oxide finish on alloy steel offers enhanced protection against rust and environmental degradation, extending service life in harsh industrial settings.
• Precision Thread Fit: Class 3A thread fit ensures tight, secure connections with minimal play, improving assembly accuracy and vibration resistance.
• Optimized Drive Engagement: The 7/32" hex drive allows for high-torque installation without stripping, facilitating efficient assembly and disassembly with standard tools.
• Full Threading for Maximum Grip: Fully threaded design distributes clamping force evenly along the entire length, enhancing holding power in various material thicknesses.
• Standardized Countersink Profile: 82° flat head with standard profile ensures flush mounting and seamless integration into prepared surfaces, improving aesthetics and safety.
• High Hardness for Durability: Rockwell C39 hardness provides excellent wear resistance, maintaining thread integrity and drive features through repeated use.

Professional Applications & Engineering Value

Engineered for industrial applications where reliability and corrosion resistance are critical, these 3/8"-16 UNC flat head screws solve common fastening challenges in machinery, structural assemblies, and heavy equipment. The black-oxide alloy steel construction combats moisture and chemical exposure, preventing premature failure in outdoor or corrosive environments. The coarse UNC threads and Class 3A fit ensure quick installation and secure locking in metals and composites, reducing assembly time while minimizing loosening from vibrations. With a fully threaded design and 82° countersink, they provide consistent clamping force and smooth surface finishing, ideal for applications requiring flush mounting without protrusions. These screws deliver dependable performance in automotive, construction, and manufacturing sectors where high tensile strength and compliance with industry standards are non-negotiable.

Specification Summary & Compliance

This product adheres to precise dimensional standards, including UNC coarse threads with Class 3A thread fit for superior tolerance control. Manufacturing and material specifications comply with ASTM F835, ensuring consistent quality and performance. Environmental and safety regulations are met through RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliance, confirming the absence of restricted substances. The right-hand threading and standardized head profile facilitate compatibility with common industrial fastening systems.