S-91440A556 1/4"-20 x 4" ASME B18.6.3 Steel Round Head Combination Phillips/Slotted Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with zinc-plated steel construction, ensuring long-term reliability in harsh industrial environments.
• High tensile strength of 60,000 psi provides dependable load-bearing capacity for demanding heavy-duty applications.
• Rockwell B70 hardness rating offers excellent durability and resistance to wear during installation and use.
• Dual Phillips/slotted drive options allow for versatile installation with standard tools, improving assembly efficiency.
• Class 2A thread fit with UNC coarse threading ensures easy alignment and secure fastening in various materials.
• Fully threaded 4" length delivers maximum grip and holding power across the entire fastener.
• Compliance with ASME B18.6.3, RoHS 3, and REACH guarantees quality, safety, and environmental standards for professional use.

Professional Applications & Engineering Value

Engineered for heavy-duty industrial and construction applications, these zinc-plated steel rounded head screws address critical challenges in corrosive environments and high-stress assemblies. The 1/4"-20 UNC coarse thread design facilitates quick installation while maintaining strong clamping force, reducing the risk of stripping in wood, metal, or composite materials. With fully threaded construction and 60,000 psi tensile strength, they provide consistent performance in structural frameworks, machinery, and equipment where vibration resistance and long-term integrity are paramount. The rounded head profile and dual Phillips/slotted drive options enhance usability across diverse job sites, making them ideal for contractors and manufacturers seeking reliable, corrosion-resistant fasteners that meet rigorous ASME B18.6.3 standards.

Specification Summary & Compliance

This 1/4-20 x 4" screw features precise Class 2A thread fit and UNC coarse threading for consistent engagement. Manufactured in compliance with ASME B18.6.3 specifications, it ensures dimensional accuracy and performance reliability. The product is fully RoHS 3 (2015/863/EU) compliant and REACH (EC 1907/2006) compliant, adhering to environmental and safety regulations for industrial use.