S-93548A550 1/4"-20 x 2" ASTM A307, SAE J429, ASME B18.5 Carriage Bolts

Key Features & Benefits at a Glance

• Superior corrosion resistance with zinc-plated steel construction, extending service life in harsh industrial environments
• Reliable anti-rotation performance thanks to the integrated square neck design that prevents spinning during installation
• Exceptional tensile strength with Grade 2 classification (60,000 psi) for heavy-duty load-bearing applications
• Optimized thread engagement through UNC coarse threading and Class 2A fit, ensuring quick assembly and vibration resistance
• Enhanced installation security with fully threaded design providing maximum grip length and holding power
• Wide bearing surface from the rounded carriage head profile, distributing pressure evenly and preventing surface damage
• Regulatory compliance assurance meeting multiple industry standards including ASTM A307, SAE J429, and ASME B18.5

Professional Applications & Engineering Value

This zinc-plated steel carriage bolt delivers critical engineering solutions for construction and industrial applications where vibration resistance and secure fastening are paramount. The square neck design effectively prevents rotation during torque application, eliminating the need for secondary locking mechanisms and reducing installation time. With Grade 2 strength classification and 60,000 psi tensile strength, it provides reliable performance in structural connections, machinery assembly, and wood-to-metal applications. The UNC coarse thread pattern ensures rapid installation in various materials while maintaining strong holding power. The combination of Rockwell B70 hardness and protective zinc plating offers durability against environmental exposure, making it ideal for outdoor structures, equipment frames, and agricultural machinery where corrosion resistance and long-term reliability are essential.

Specification Summary & Compliance

This carriage bolt features precise Class 2A thread fit tolerance for consistent performance and meets rigorous manufacturing standards including ASTM A307, SAE J429, and ASME B18.5. The fastener maintains dimensional accuracy with 1/4"-20 UNC coarse threading and right-hand thread direction. Compliance with RoHS 3 (2015/863/EU) ensures environmental responsibility while delivering the mechanical properties required for demanding industrial applications, including the specified 60,000 psi tensile strength and Rockwell B70 hardness rating.