S-90185A818 5/8"-11 x 3" ASME B18.5, SAE J429 Carriage Bolts

Key Features & Benefits at a Glance

• Exceptional load-bearing capacity with Grade 5 classification and 120,000 psi tensile strength for reliable performance in demanding applications.
• Superior corrosion resistance provided by zinc-plated steel coating, extending service life in harsh or outdoor environments.
• Secure, non-rotating installation due to the integrated square neck design, preventing spin-out during tightening and ensuring stable fastening.
• Wide, rounded carriage head offers a larger bearing surface for enhanced load distribution and reduced risk of material damage.
• Coarse UNC threading with Class 2A fit allows for quick assembly and disassembly, even in materials prone to debris accumulation.
• Full threading along the 3" length provides versatile grip range and consistent clamping force across various material thicknesses.
• Compliance with major industry standards including ASME B18.5 and SAE J429, ensuring consistent quality and interchangeability.

Professional Applications & Engineering Value

This Grade 5 zinc-plated steel carriage bolt is engineered to address common challenges in heavy-duty industrial and construction applications, such as structural connections, machinery assembly, and wood-to-metal fastening. The zinc plating delivers reliable corrosion resistance, crucial for outdoor or high-moisture environments, while the square neck securely locks into materials to prevent rotation during torque application—eliminating the need for additional anti-rotation hardware. With a coarse UNC thread and Class 2A thread fit, it ensures easy installation and robust performance even in softer materials or where vibration resistance is required. The fully threaded design and 120,000 psi tensile strength provide dependable clamping force, making it ideal for securing timber, steel frames, and equipment where long-term reliability is non-negotiable.

Specification Summary & Compliance

This carriage bolt adheres to ASME B18.5 and SAE J429 specifications, with a 5/8"-11 UNC coarse thread and Class 2A thread fit ensuring dimensional accuracy and interchangeability. It meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliance, confirming the absence of restricted hazardous substances. Manufactured from zinc-plated steel with a Rockwell C25 hardness, it maintains consistent mechanical properties and durability across industrial uses.