S-90185A128 3/8"-16 x 4" ASME B18.5, SAE J429 Carriage Bolts

Key Features & Benefits at a Glance

• Superior corrosion resistance with black-oxide steel finish, extending service life in harsh environments
• Exceptional load-bearing capacity with Grade 5 classification and 120,000 PSI tensile strength for demanding applications
• Secure anti-rotation design featuring a square neck that prevents spinning during installation and use
• Reliable thread engagement with UNC coarse threading and Class 2A fit for quick assembly and vibration resistance
• Enhanced durability from Rockwell C25 hardness, maintaining structural integrity under heavy stress
• Full-threaded convenience allowing for maximum adjustability and grip length in various material thicknesses
• Regulatory compliance assurance meeting ASME B18.5, SAE J429, RoHS 3, and REACH standards for quality and safety

Professional Applications & Engineering Value

This Grade 5 carriage bolt delivers critical performance in structural and heavy machinery applications where vibration resistance and corrosion protection are paramount. The black-oxide steel construction provides a durable barrier against moisture and chemicals, significantly reducing maintenance needs in outdoor or industrial settings. Its square neck design securely locks into materials, preventing rotation during torque application and ensuring stable fastening in wood-to-metal or structural steel connections. The UNC coarse threading with Class 2A fit enables rapid installation while maintaining strong holding power in agricultural equipment, trailer assemblies, and construction frameworks. With full threading along the 4" length, it accommodates varying material thicknesses in framing, machinery guards, and transportation equipment without compromising strength.

Specification Summary & Compliance

This carriage bolt maintains precise Class 2A thread fit tolerances with 3/8"-16 UNC coarse threading and right-hand orientation. Manufacturing adheres to ASME B18.5 and SAE J429 specifications for dimensional accuracy and performance consistency. Regulatory compliance includes RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental standards, ensuring safe use across industrial sectors. The fastener delivers verified mechanical properties including 120,000 PSI tensile strength and Rockwell C25 hardness, meeting rigorous quality requirements for industrial fastening applications.