S-91274A180 1/4"-20 x 1 1/2" 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 provides superior resistance to mechanical stress and prevents fastener failure in demanding applications.
• Advanced zinc-flake coating offers outstanding corrosion resistance, significantly extending the service life of the fastener in harsh industrial environments.
• Precise Class 3A thread fit ensures reliable, vibration-resistant assemblies with consistent clamping force and reduced risk of loosening.
• High Rockwell C37 hardness enhances wear resistance and maintains thread integrity during repeated installation and high-load conditions.
• Partially threaded design allows for precise positioning and secure fastening where a specific unthreaded shoulder is required.
• Standard hex socket drive (3/16") enables high-torque installation with common tools, facilitating efficient assembly and disassembly.
• Compliance with major industry standards (ASME B18.3, ASTM A574) guarantees consistent quality, dimensional accuracy, and material performance.

Professional Applications & Engineering Value

Engineered for high-stakes industrial applications, this 1/4"-20 UNC Socket Head Cap Screw provides a robust fastening solution where reliability is non-negotiable. The zinc-flake-coated alloy steel construction directly combats corrosion, a common failure point in machinery, automotive, and outdoor equipment. Its 170,000 PSI tensile strength and coarse UNC thread make it ideal for securing heavy-duty components in vibrating systems, preventing joint failure. The partially threaded shank offers design flexibility, allowing engineers to use the unthreaded portion as a precision pilot or shear plane, enhancing structural integrity in complex assemblies and reducing the need for additional components.

Specification Summary & Compliance

This fastener features a 1/4"-20 UNC thread with a Class 3A fit for high precision. It is manufactured in accordance with ASME B18.3 and ASTM A574 specifications, ensuring dimensional consistency and material quality. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming it is free of hazardous substances and safe for use in regulated markets.