S-91236A552 1/4"-20 x 2 1/2" ASME B18.2.1, ASTM A307 Low-Strength Steel Hex Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with zinc plating that protects against rust in demanding industrial environments
• High tensile strength of 60,000 psi ensures reliable performance under heavy loads and vibration
• Rockwell B69 hardness provides excellent durability and resistance to wear during installation and use
• Class 2A thread fit offers consistent, easy assembly while maintaining secure fastening integrity
• External hex drive design allows for high-torque installation with standard tools, reducing assembly time
• Partial threading configuration enables optimal grip strength where full thread engagement isn't required
• Coarse UNC thread pattern provides quick installation and superior resistance to loosening in vibration-prone applications

Professional Applications & Engineering Value

This 1/4-20 UNC hex head screw delivers exceptional engineering value through its ASTM A307 steel construction and zinc plating surface treatment. The combination of 60,000 psi tensile strength and Rockwell B69 hardness addresses critical industrial challenges where fastener failure can lead to equipment downtime or safety concerns. The coarse thread design and partial threading make it ideal for applications requiring rapid assembly in structural steel connections, machinery frames, and heavy equipment where vibration resistance is paramount. The external hex drive accommodates high torque values during installation, ensuring secure fastening in demanding industrial applications while the 2 1/2" length provides sufficient engagement for thick materials and structural components.

Specification Summary & Compliance

This hex head screw features precise Class 2A thread fit with 1/4"-20 UNC coarse threads and right-hand threading direction. Manufactured to ASME B18.2.1 specifications using ASTM A307 steel material, the fastener ensures dimensional accuracy and mechanical consistency. The product maintains full compliance with RoHS 3 (2015/863/EU) regulations and REACH (EC 1907/2006) requirements, confirming environmental responsibility and material safety standards for industrial use worldwide.