S-91274A188 1/4"-20 x 2" ASME B18.3, ASTM A574, ASTM B117 Alloy Steel Socket Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 170,000 psi ensures reliable performance under high-stress conditions, reducing the risk of fastener failure in demanding applications.
• Superior corrosion resistance provided by the zinc-flake coating, extending service life and maintaining integrity in harsh or outdoor environments.
• Precise Class 3A thread fit offers tighter tolerances for secure, vibration-resistant assemblies, minimizing loosening in machinery and equipment.
• High hardness (Rockwell C37) enhances wear resistance and durability, ideal for repeated disassembly and reassembly in maintenance operations.
• Hex socket drive design allows for high torque application and easy installation in confined spaces, improving assembly efficiency.
• Compliance with ASME B18.3, ASTM A574, and ASTM B117 guarantees consistent quality and interoperability with standard components, simplifying procurement and inventory management.
• RoHS 3 and REACH compliance ensures environmental and regulatory safety, making it suitable for global supply chains and sensitive industries.

Professional Applications & Engineering Value

This Socket Head Cap Screw is engineered from zinc-flake-coated alloy steel to address critical challenges in industrial settings, such as vibration-induced loosening and corrosion in high-moisture or chemical environments. The 1/4"-20 UNC coarse threads with a Class 3A fit provide excellent grip and alignment in metal-to-metal assemblies, reducing the need for frequent retightening in machinery, automotive, and aerospace applications. Its partially threaded design allows for precise clamping force distribution, preventing damage to sensitive components. With a 2" length and hex drive, it facilitates quick installation in tight spaces, enhancing productivity on assembly lines while maintaining high tensile strength for heavy-duty structural connections.

Specification Summary & Compliance

This screw adheres to precise dimensional standards, including Class 3A thread fit for superior accuracy and UNC coarse threads per ASME B18.3. It meets material specifications under ASTM A574 and corrosion testing per ASTM B117. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006), ensuring it is free from hazardous substances and suitable for regulated industrial use.