S-91236A544 1/4"-20 x 1 1/4" ASME B18.2.1, ASTM A307 Low-Strength Steel Hex Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with zinc plating for extended service life in demanding environments
• High tensile strength of 60,000 psi ensures reliable performance under heavy loads and vibration
• Class 2A thread fit provides consistent, reliable assembly with standard nuts and tapped holes
• Partially threaded design offers optimal clamping force distribution and prevents thread damage
• External hex drive enables high-torque installation with common tools for efficient assembly
• Rockwell B69 hardness maintains thread integrity and prevents stripping during repeated use
• UNC coarse threading allows for faster installation and better performance in softer materials

Professional Applications & Engineering Value

These 1/4"-20 UNC hex head screws deliver exceptional engineering value across industrial applications where vibration resistance and structural integrity are critical. The zinc plated steel construction provides essential corrosion protection for machinery, equipment frames, and structural assemblies exposed to moderate environmental conditions. The partially threaded design concentrates clamping force precisely where needed, preventing joint loosening in dynamic load scenarios. With coarse UNC threading, these screws install quickly in steel, aluminum, and composite materials, reducing assembly time while maintaining 60,000 psi tensile strength for heavy-duty fastening requirements. The external hex drive accommodates high torque applications, making them ideal for maintenance, manufacturing, and construction projects requiring reliable, reusable fasteners.

Specification Summary & Compliance

Manufactured to precise Class 2A thread fit tolerances with 1/4"-20 UNC coarse thread specifications. These hex head screws conform to ASME B18.2.1 dimensional standards and ASTM A307 material requirements. Full compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations ensures safe use across global industrial markets. The combination of Rockwell B69 hardness and controlled threading delivers consistent performance meeting industrial fastening specifications.