S-90185A589 5/16"-18 x 1 1/4" ASME B18.5, SAE J429 Carriage Bolts

Key Features & Benefits at a Glance

• Superior anti-rotation performance thanks to the integrated square neck design, preventing the bolt from turning during installation and ensuring a secure, permanent hold.
• Exceptional tensile strength of 120,000 psi (Grade 5) provides reliable performance for high-stress applications, reducing the risk of fastener failure.
• Enhanced corrosion resistance from the zinc-plated steel construction, extending the bolt's service life in demanding industrial and outdoor environments.
• Optimized for quick and easy installation with a fully threaded UNC coarse thread and right-hand direction, allowing for faster assembly times.
• Consistent and reliable fit ensured by Class 2A thread fit, promoting smooth engagement with nuts and reducing cross-threading issues.
• Durable and impact-resistant with a Rockwell C25 hardness, maintaining structural integrity under heavy loads and vibration.
• Broad compatibility and assured quality through compliance with ASME B18.5 standards, meeting rigorous engineering specifications.

Professional Applications & Engineering Value

This Grade 5 zinc-plated steel carriage bolt is engineered to solve critical challenges in industrial assembly and construction. The square neck is a key feature, designed to embed securely into wood or metal, effectively preventing rotation and eliminating the need for additional locking mechanisms. This is particularly valuable in structural applications like wood-to-metal connections, trailer building, and heavy machinery, where vibration can loosen standard fasteners. The combination of high tensile strength and a coarse UNC thread ensures a robust and reliable connection that can withstand significant dynamic loads. The zinc plating provides a sacrificial layer that fights corrosion, making it an ideal choice for outdoor infrastructure, agricultural equipment, and other applications exposed to the elements, thereby reducing long-term maintenance costs and improving project longevity.

Specification Summary & Compliance

This carriage bolt is manufactured to precise dimensional standards, including a Class 2A thread fit for consistent assembly. It conforms to the ASME B18.5 standard and meets the material specifications of SAE J429 for Grade 5. The product is also compliant with major environmental regulations, including RoHS 3 (2015/863/EU) and REACH (EC 1907/2006), ensuring it is free from hazardous substances and safe for use in regulated markets.