S-91255A112 4-40 x 5/8" ASTM F835 Steel Button Head Hex-Drive Screws

Key Features & Benefits at a Glance

• Exceptional corrosion resistance with black-oxide coating, ideal for harsh industrial environments
• Superior holding power from 120,000 psi tensile strength and Rockwell C39 hardness for demanding applications
• Precise Class 3A thread fit ensures secure, vibration-resistant fastening in critical assemblies
• Quick installation with 1/16" hex drive and rounded button head design for flush, low-profile mounting
• Reliable coarse threading (UNC) provides faster engagement and reduced cross-threading risks
• Full-length threading maximizes grip strength across the entire 5/8" length for uniform load distribution
• Compliance assurance with ASME B18.3, ASTM F835, RoHS 3, and REACH standards for global industrial use

Professional Applications & Engineering Value

Engineered for precision assemblies requiring high-strength fastening solutions, these 4-40 UNC rounded head screws address critical industrial challenges. The black-oxide alloy steel construction combats corrosion in manufacturing, electronics, and automotive environments, while the Class 3A thread fit eliminates loosening under vibration. The button head profile with 1/16" hex drive enables secure, low-clearance installations in confined spaces. Fully threaded design ensures consistent clamping force across the 5/8" length, making these coarse thread screws ideal for high-stress applications where reliability and regulatory compliance are paramount.

Specification Summary & Compliance

This fastener maintains precision Class 3A thread tolerances per UNC standards with coarse threading for optimal performance. Manufacturing adheres to ASME B18.3 and ASTM F835 specifications, ensuring dimensional accuracy and mechanical consistency. Full compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations guarantees environmental safety and global market suitability for industrial procurement.