S-91440A537 1/4"-20 x 1/2" ASME B18.6.3 Steel Round Head Combination Phillips/Slotted Screws

Key Features & Benefits at a Glance

• Enhanced corrosion resistance with zinc-plated steel construction for reliable performance in demanding industrial environments
• Superior torque transfer through dual Phillips/Slotted drive design, reducing tool slippage and installation time
• High tensile strength rating of 60,000 psi ensures dependable fastening in heavy-duty applications
• Optimized thread engagement with Class 2A UNC coarse threads for quick assembly and vibration resistance
• Consistent material hardness at Rockwell B70 provides excellent durability and resistance to deformation
• Versatile drive compatibility with No. 3 Phillips and standard slotted tools for flexible installation options
• Full threading coverage along the 1/2" length maximizes grip strength and load distribution

Professional Applications & Engineering Value

This zinc-plated steel rounded head screw delivers exceptional engineering value for industrial assembly applications where corrosion resistance and high tensile strength are critical. The combination of UNC coarse threading and Class 2A thread fit ensures rapid installation while maintaining precise tolerances in machinery, equipment manufacturing, and structural frameworks. The fully threaded design provides maximum engagement surface area, distributing stress evenly to prevent joint failure under vibration or heavy loads. The dual Phillips/Slotted drive system offers installation flexibility, allowing technicians to use multiple tool types without compromising torque transfer efficiency. These rounded head fasteners are particularly valuable in applications requiring both aesthetic appeal and mechanical reliability, making them ideal for visible assemblies in industrial equipment, automotive components, and construction projects where both performance and appearance matter.

Specification Summary & Compliance

This 1/4-20 UNC coarse thread screw features precise Class 2A thread fit tolerances and complies with ASME B18.6.3 manufacturing specifications. The product meets stringent regulatory requirements including RoHS 3 (2015/863/EU) compliance and REACH (EC 1907/2006) compliance, ensuring environmental safety and material quality. Manufacturing adheres to dimensional standards with 0.25" thread diameter, 1/2" length, and 0.472" head diameter for consistent performance across industrial applications.