S-91306A283 1/4"-28 x 3/8" ASTM F835 Steel Button Head Hex-Drive Screws

Key Features & Benefits at a Glance

• Exceptional durability with zinc-plated alloy steel construction providing superior corrosion resistance in demanding industrial environments
• Precise thread engagement through Class 3A UNF fine threading ensures secure fastening and vibration resistance
• High-strength performance with 120,000 psi tensile strength and Rockwell C39 hardness for heavy-duty applications
• Easy installation and removal with 5/32" hex drive design allowing efficient tool access in confined spaces
• Reliable full-thread coverage along the 3/8" length provides maximum grip strength and load distribution
• Standard-compliant quality meeting ASME B18.3 and ASTM F835 specifications for consistent performance
• Environmentally responsible manufacturing with RoHS 3 and REACH compliance for sustainable operations

Professional Applications & Engineering Value

These zinc-plated alloy steel rounded head screws with 1/4"-28 UNF Class 3A threading deliver critical engineering solutions where precision and reliability are paramount. The fine thread spacing provides superior resistance to vibration loosening in machinery, automotive, and aerospace applications. The rounded button head profile with hex drive compatibility offers flush mounting while maintaining excellent torque transmission. Engineered for high-strength industrial applications, these fasteners prevent thread stripping and maintain integrity under extreme stress conditions up to 120,000 psi. The combination of alloy steel material and protective zinc plating ensures long-term performance in corrosive environments, making them ideal for manufacturing equipment, structural assemblies, and precision instruments requiring dependable Class 3A thread fit accuracy.

Specification Summary & Compliance

This rounded head screw features precision Class 3A thread fit with 1/4"-28 UNF fine threading and full thread coverage along the 3/8" length. Manufacturing complies with ASME B18.3 and ASTM F835 standards, ensuring dimensional accuracy and performance consistency. The product meets RoHS 3 (2015/863/EU) compliance for hazardous substance restrictions and REACH (EC 1907/2006) requirements for chemical safety, validated as of January 17, 2023. The zinc-plated alloy steel construction maintains Rockwell C39 hardness and 120,000 psi tensile strength across all operational conditions.