S-91255A821 3/8"-16 x 1/4" 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 high-stress conditions, reducing the risk of fastener failure in demanding applications.
• Superior corrosion resistance from the black-oxide finish on alloy steel extends service life in harsh industrial environments, minimizing maintenance and replacement costs.
• Precise Class 3A thread fit guarantees tight, secure fastening with minimal backlash, enhancing assembly integrity and vibration resistance.
• Fully threaded design provides consistent engagement along the entire length, offering versatile installation options and improved load distribution.
• Hex drive compatibility with a 7/32" drive allows for efficient torque application using standard tools, speeding up assembly and disassembly processes.
• Rounded button head profile reduces the risk of snagging and provides a low-profile, aesthetically clean finish for applications where clearance is a concern.
• Compliance with major standards including ASME B18.3 and ASTM F835 ensures consistent quality and interoperability in regulated industrial settings.

Professional Applications & Engineering Value

Engineered for rigorous industrial use, these 3/8"-16 UNC rounded head screws address common challenges in machinery assembly, automotive components, and structural frameworks. The black-oxide alloy steel construction combats corrosion effectively, making them ideal for environments exposed to moisture or chemicals. With a coarse thread and Class 3A fit, they deliver superior holding power and ease of installation in materials like cast iron or soft metals, reducing the likelihood of cross-threading. The hex drive design ensures high torque transmission without slippage, streamlining maintenance operations. Fully threaded for maximum grip, these screws provide reliable fastening in high-vibration applications, ensuring long-term operational safety and reducing downtime.

Specification Summary & Compliance

This product adheres to precise dimensional standards, including UNC coarse threads with a Class 3A thread fit for tight tolerances and consistent performance. Manufacturing and material specifications comply with ASME B18.3 and ASTM F835, ensuring reliability in mechanical fastening. Additionally, it meets environmental regulations such as RoHS 3 (2015/863/EU) and REACH (EC 1907/2006), confirming the absence of hazardous substances for safe use in global markets.