S-91274A216 1/4"-20 x 3 1/2" ASME B18.3, ASTM A574, ASTM B117 Alloy Steel Socket Head Screws

Key Features & Benefits at a Glance

• Exceptional corrosion resistance with zinc-flake coating, ensuring long-term reliability in harsh industrial environments
• High tensile strength of 170,000 psi for secure fastening in heavy-duty applications without failure
• Precise Class 3A thread fit delivers superior engagement and vibration resistance in critical assemblies
• Rockwell C37 hardness provides excellent wear resistance and durability under repeated use
• Partially threaded design allows for controlled clamping force and easier alignment in complex setups
• Standard hex socket drive enables easy installation with common tools, reducing assembly time
• Coarse UNC threading ensures quick installation and reliable performance in various materials

Professional Applications & Engineering Value

This 1/4"-20 UNC Socket Head Cap Screw is engineered to address common industrial fastening challenges, such as vibration loosening and corrosion-induced failure. The zinc-flake-coated alloy steel construction provides a robust barrier against moisture and chemicals, making it ideal for outdoor equipment, machinery, and automotive applications. With its Class 3A thread fit and coarse thread spacing, it ensures rapid, secure installation in high-stress environments, reducing maintenance downtime. The partially threaded rod design offers precise load distribution, preventing joint slippage in heavy-duty industrial assemblies where reliability is critical.

Specification Summary & Compliance

This screw meets ASME B18.3 and ASTM A574 specifications, ensuring dimensional accuracy and manufacturing consistency. It features a Class 3A thread fit for tight tolerances and UNC coarse threading with a 1/4"-20 thread size. Compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) confirms environmental and safety standards, supporting sustainable industrial practices.