S-90044A424 1/4"-20 x 1 7/8" ASME B18.3, ASTM A574 Alloy Steel Socket Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 170,000 psi ensures reliable performance in high-stress applications, reducing the risk of fastener failure.
• Superior corrosion resistance from the black-oxide finish extends service life in harsh industrial environments, minimizing maintenance needs.
• Precise Class 3A thread fit provides tighter tolerances for secure fastening and improved vibration resistance in machinery assemblies.
• High hardness rating (Rockwell C37) offers excellent wear resistance, maintaining thread integrity through repeated use.
• Standard hex drive design allows for easy installation with common tools while providing high torque capability.
• Compliance with major industry standards including ASME B18.3 ensures consistent quality and interchangeability across applications.
• Partially threaded design combines the holding power of full threads with the alignment benefits of an unthreaded shoulder.

Professional Applications & Engineering Value

These black-oxide alloy steel socket head cap screws deliver critical performance advantages in demanding industrial settings. The combination of 170,000 psi tensile strength and Rockwell C37 hardness addresses common failure points in heavy machinery, automotive, and equipment manufacturing where vibration and dynamic loads challenge fastener integrity. The Class 3A thread fit with UNRC coarse threads ensures rapid assembly while maintaining secure connections in high-vibration environments. The black-oxide surface treatment provides essential corrosion protection without compromising dimensional accuracy, making these inch system fasteners ideal for precision applications requiring both durability and consistent performance. The partially threaded configuration offers superior clamping force distribution while facilitating precise component alignment.

Specification Summary & Compliance

This socket head cap screw features precision Class 3A thread fit with 1/4"-20 UNRC coarse threads and right-hand thread direction. Manufactured to ASME B18.3 specifications using ASTM A574 alloy steel, these fasteners maintain strict dimensional tolerances throughout production. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use across global markets. Critical dimensions include 1-7/8" length with 1" minimum thread length, 3/8" head diameter, and 3/16" hex drive size for standardized tool compatibility.