S-90185A640 3/8"-16 x 4" ASME B18.5, SAE J429 Carriage Bolts

Key Features & Benefits at a Glance

• Superior anti-rotation performance with a square neck design that securely locks into materials, preventing the bolt from spinning during installation and ensuring stable, reliable connections.
• Exceptional tensile strength and durability with Grade 5 classification and 120,000 psi tensile strength, making it ideal for high-stress applications in construction and industrial settings.
• Enhanced corrosion resistance through zinc-plated steel construction, providing reliable protection against rust and extending the fastener's service life in harsh environments.
• Wide compatibility and easy installation with UNC coarse threading and Class 2A fit, ensuring smooth engagement with standard nuts and reducing assembly time.
• Optimized for heavy-duty use featuring a Rockwell C25 hardness and fully threaded design, offering consistent strength and load distribution along the entire bolt length.
• Secure and vibration-resistant fastening due to the rounded carriage head and square neck, which work together to maintain tight connections under dynamic loads.
• Compliance with major industry standards including ASME B18.5 and SAE J429, guaranteeing quality, reliability, and interchangeability in professional applications.

Professional Applications & Engineering Value

This 3/8"-16 Grade 5 zinc-plated steel carriage bolt is engineered to address common challenges in industrial and construction assemblies, such as loosening under vibration and corrosion in outdoor settings. The square neck design effectively counters rotation during tightening, eliminating the need for additional locking mechanisms and speeding up installation in wood, metal, and structural frameworks. Made from zinc-plated steel, it resists environmental degradation, while the UNC coarse thread and Class 2A fit ensure precise, durable connections in heavy machinery, agricultural equipment, and building projects. With a fully threaded right-hand configuration, it provides uniform clamping force, reducing stress concentrations and enhancing overall assembly integrity for long-term reliability.

Specification Summary & Compliance

This carriage bolt adheres to precise dimensional standards, including a Class 2A thread fit for consistent engagement and UNC coarse threading (3/8"-16) for robust performance. It meets ASME B18.5 and SAE J429 specifications, ensuring high-quality manufacturing and material consistency. Additionally, the product is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its safety and environmental responsibility for global industrial use.