S-91255A031 1/4"-28 x 2 1/2" 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 needs.
• Precision Class 3A thread fit guarantees tight, secure connections with minimal backlash, ideal for fine-threaded assemblies requiring exact tolerances.
• Fully threaded design provides consistent engagement along the entire length, enhancing load distribution and vibration resistance.
• Hex drive (5/32") with rounded button head allows for easy installation in confined spaces while offering a low-profile, snag-resistant finish.
• Compliance with ASME B18.3 and ASTM F835 ensures adherence to industry-recognized standards for dimensional accuracy and mechanical properties.
• RoHS 3 and REACH compliance confirms environmental and safety regulations are met, supporting sustainable and safe usage in global markets.

Professional Applications & Engineering Value

Engineered for industrial applications where precision and durability are critical, this 1/4"-28 UNF screw excels in machinery, automotive, and aerospace assemblies. The black-oxide alloy steel construction combats corrosion effectively, addressing common issues like rust in humid or chemically exposed settings. Its fine thread spacing and Class 3A fit provide superior clamping force and resistance to loosening under vibration, making it ideal for components requiring repeated adjustments or high integrity. The rounded head style reduces the risk of snagging, while the hex drive ensures quick, tool-friendly installation. By meeting ASME B18.3 and ASTM F835 standards, it delivers consistent performance in high-tensile-strength scenarios, from heavy-duty equipment to precision instruments.

Specification Summary & Compliance

This product features a 1/4"-28 UNF fine thread with Class 3A tolerance for precise fit, a length of 2 1/2", and full threading. It complies with ASME B18.3 for dimensional standards and ASTM F835 for mechanical properties, and is verified to be RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliant, ensuring adherence to environmental and safety regulations.