S-91247A558 1/4"-20 x 4" ASME B18.2.1, SAE J429 Medium-Strength Grade 5 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional strength for demanding applications with Grade 5 classification and 120,000 psi tensile strength
• Superior corrosion resistance provided by the zinc plating, extending service life in harsh industrial environments
• Reliable coarse threading (UNC) for faster installation and reduced cross-threading risk in coarse materials
• Optimized for high-torque applications featuring an external hex drive and hex head for secure, easy driving
• Precision thread fit (Class 2A) ensuring consistent performance and secure fastening in assembly lines
• Partially threaded design offering enhanced clamping force control for specific joint requirements
• Full regulatory compliance meeting ASME B18.2.1, SAE J429, RoHS 3, and REACH standards for global industrial use

Professional Applications & Engineering Value

Engineered for heavy-duty industrial applications, this 1/4-20 UNC Grade 5 Hex Head Screw solves critical fastening challenges in machinery, structural steel, and equipment assembly. The zinc plated steel construction provides a durable barrier against rust and corrosion, significantly increasing component lifespan in environments exposed to moisture and chemicals. The coarse thread design ensures rapid installation and superior holding power in softer materials and castings, while the external hex drive allows for high torque application with standard tools, preventing stripping and ensuring reliable connections. With its partially threaded shank, it delivers precise clamping force, making it ideal for applications where vibration resistance and joint integrity are paramount. This screw is specifically designed to meet the rigorous demands of industrial fastening where failure is not an option.

Specification Summary & Compliance

This 4" length hex head screw features a 1/4"-20 UNC coarse thread with Class 2A thread fit for consistent dimensional accuracy. It is manufactured from steel with a zinc plated finish and meets ASME B18.2.1 and SAE J429 specifications. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring it is free from hazardous substances and suitable for use in regulated industrial markets.