S-90280A539 1/4"-20 x 5/8" ASME B18.6.3 Steel Fillister Head Slotted Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with zinc-plated steel construction, extending service life in demanding industrial environments
• Exceptional holding power with 60,000 psi tensile strength and Rockwell B69 hardness for reliable fastening in high-stress applications
• Easy installation and removal with standard slotted drive design compatible with common hand tools
• Optimized thread engagement through Class 2A thread fit and coarse UNC threading for secure connections and reduced cross-threading risks
• Enhanced clearance capability with high-profile fillister head design, ideal for counterbored applications where space is limited
• Full-length threading provides consistent grip along the entire 5/8" length for maximum fastening security
• Regulatory compliance assurance meeting ASME B18.6.3 standards and environmental regulations including RoHS 3 and REACH

Professional Applications & Engineering Value

This zinc-plated steel fillister head screw delivers critical engineering advantages for industrial assembly applications. The high-profile rounded head design provides superior bearing surface contact while allowing deeper counterbore seating, solving clearance issues in compact machinery and equipment. The 1/4-20 UNC coarse threading ensures rapid installation and reliable performance in vibration-prone environments, while the Class 2A thread fit maintains precision alignment during assembly. The zinc plating offers essential corrosion protection for manufacturing facilities, automotive applications, and electronic enclosures exposed to moisture or chemical agents. With full threading along the 5/8" length, this screw maintains consistent clamping force across the entire engagement area, preventing joint loosening in dynamic load conditions common to industrial machinery and equipment frames.

Specification Summary & Compliance

This 1/4-20 UNC screw features precise Class 2A thread fit tolerances with coarse thread spacing for optimal engagement. Manufacturing complies with ASME B18.6.3 standards for dimensional accuracy and performance reliability. The product meets RoHS 3 (2015/863/EU) compliance for hazardous substance restrictions and REACH (EC 1907/2006) regulations for chemical safety, ensuring environmental responsibility in industrial supply chains.