S-90185A259 5/8"-11 x 5 1/2" ASME B18.5, SAE J429 Carriage Bolts

Key Features & Benefits at a Glance

• Superior anti-rotation performance with a square neck that locks securely into materials, preventing the bolt from turning during installation and under vibration.
• Exceptional tensile strength and hardness with a Grade 5 rating, 120,000 psi tensile strength, and Rockwell C25 hardness for reliable performance in demanding structural and heavy machinery applications.
• Enhanced corrosion resistance provided by the zinc-plated steel construction, extending the bolt's service life in outdoor or humid industrial environments.
• Optimized for quick installation featuring a fully threaded UNC coarse pattern and Class 3A thread fit, ensuring fast, secure engagement and reducing assembly time.
• Secure and flush mounting with a wide, rounded carriage head design that sits neatly against surfaces while the square neck provides positive locking.
• Proven reliability in heavy-duty applications such as construction, agricultural equipment, and trailer assembly, thanks to its robust material and design.
• Broad material compatibility with the coarse 5/8"-11 UNC thread, making it suitable for use in wood, metal, and other common industrial materials.

Professional Applications & Engineering Value

This Grade 5 zinc-plated steel carriage bolt is engineered to address critical fastening challenges in industrial and construction settings. The combination of a square neck and rounded carriage head effectively counters rotational forces, a common failure point in vibrating machinery and structural frameworks. Its fully threaded UNC coarse pattern with a precise Class 3A thread fit ensures rapid, secure installation, minimizing labor time while maximizing joint integrity. The zinc plating provides a protective barrier against corrosion, which is essential for outdoor applications, agricultural equipment, and trailer manufacturing. With a high 120,000 psi tensile strength and Rockwell C25 hardness, this bolt maintains clamp load under extreme stress, preventing loosening and structural compromise in heavy-duty assemblies.

Specification Summary & Compliance

This carriage bolt features a 5/8"-11 UNC coarse thread with a Class 3A thread fit for precise dimensional accuracy and reliable engagement. It is manufactured in compliance with ASME B18.5 and SAE J429 standards, ensuring consistent quality and performance. The product is also verified to be RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, meeting stringent environmental and safety regulations for industrial use.