S-90117A575 1/4"-20 x 3 1/2" ASME B18.3 Alloy Steel Wire-Lockable Socket Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 170,000 psi ensures reliable performance in high-stress industrial applications, reducing the risk of fastener failure.
• Superior corrosion resistance from Black-Oxide Alloy Steel extends service life in harsh environments, minimizing maintenance and replacement costs.
• Precision Class 3A thread fit provides tighter tolerances for secure, vibration-resistant connections in critical assemblies.
• Partially threaded design with 1" minimum thread length allows for optimal clamping force and easier alignment in varied material thicknesses.
• Hex socket drive enables high-torque installation with standard tools, preventing stripping and ensuring consistent fastening.
• Compliance with ASME B18.3, RoHS 3, and REACH guarantees adherence to industry standards and environmental regulations for global supply chain compatibility.
• Rockwell C37 hardness offers excellent wear resistance, maintaining thread integrity through repeated use and disassembly.

Professional Applications & Engineering Value

This 1/4"-20 UNC Socket Head Cap Screw is engineered to address common industrial challenges such as vibration loosening and corrosion in heavy machinery, automotive, and aerospace assemblies. The Black-Oxide Alloy Steel construction provides a durable barrier against moisture and chemicals, while the coarse thread spacing and Class 3A fit ensure rapid installation and reliable retention in high-vibration environments. Its partially threaded shank allows for precise load distribution, making it ideal for securing components like motor mounts, hydraulic fixtures, and structural frames where strength and longevity are critical. The hex drive design facilitates access in confined spaces, streamlining maintenance and reducing assembly time.

Specification Summary & Compliance

This screw features a 1/4"-20 UNC thread with Class 3A precision fit and coarse thread spacing for robust engagement. Manufactured to ASME B18.3 specifications, it ensures dimensional accuracy and interchangeability. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, supporting environmentally responsible sourcing and use in global markets.