S-90185A121 3/8"-16 x 1 1/4" 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
• Enhanced corrosion resistance from black-oxide steel coating, extending service life in various industrial environments
• Non-rotating installation security through integrated square neck design that locks into materials during tightening
• Superior thread engagement with UNC coarse threading and Class 2A fit for faster assembly and reduced cross-threading risk
• Optimized head design featuring wide, rounded carriage profile for increased bearing surface and reduced surface damage
• Full-threaded convenience allowing installation at any point along the bolt's length for versatile positioning
• Consistent hardness performance with Rockwell C25 rating ensuring durability and resistance to wear

Professional Applications & Engineering Value

This Grade 5 carriage bolt delivers critical engineering solutions for industrial fastening challenges where vibration resistance and structural integrity are paramount. The black-oxide steel construction provides essential corrosion protection for outdoor equipment, agricultural machinery, and construction applications exposed to environmental elements. The square neck carriage bolt design prevents rotation during nut tightening, eliminating the need for secondary locking mechanisms in wood-to-metal connections, trailer assemblies, and structural framing. With its UNC coarse thread pattern and fully threaded configuration, installation becomes significantly faster in production environments while maintaining 120,000 psi tensile strength for heavy-duty applications. The combination of Rockwell C25 hardness and Class 2A thread fit ensures consistent performance in high-vibration settings where fastener failure is not an option.

Specification Summary & Compliance

This carriage bolt maintains precise Class 2A thread fit tolerances with UNC coarse thread (3/8"-16) specifications. Manufacturing complies with ASME B18.5 and SAE J429 standards for dimensional accuracy and performance reliability. The product meets RoHS 3 (2015/863/EU) compliance for hazardous substance restrictions and REACH (EC 1907/2006) regulations for chemical safety, ensuring environmental responsibility in industrial supply chains.