S-90185A109 5/16"-18 x 5/8" ASME B18.5, SAE J429 Carriage Bolts

Key Features & Benefits at a Glance

• Superior 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 finish, extending service life in various industrial environments
• Secure anti-rotation locking through integrated square neck design that prevents spinning during installation
• Optimized thread engagement with coarse UNC threading and Class 2A fit ensuring quick assembly and vibration resistance
• Wide bearing surface from rounded carriage head design that distributes clamping force effectively
• Consistent mechanical properties with Rockwell C25 hardness providing dependable durability under stress
• Full thread coverage along the entire 5/8" length for maximum fastening versatility

Professional Applications & Engineering Value

This Grade 5 carriage bolt delivers exceptional engineering value through its black-oxide steel construction and specialized design features. The square neck carriage bolt configuration provides critical anti-rotation capability, solving the common problem of fastener spin during torque application in wood-to-metal and structural connections. The coarse UNC thread pattern ensures rapid installation in timber, structural steel, and heavy equipment applications where vibration resistance is paramount. With 120,000 psi tensile strength and controlled hardness, this fastener maintains integrity under dynamic loads and shock conditions typical in construction, agricultural machinery, and transportation equipment. The combination of fully threaded design and precise Class 2A thread fit guarantees consistent clamping force distribution across the entire engagement length.

Specification Summary & Compliance

This carriage bolt maintains precise dimensional accuracy with Class 2A thread fit per UNC standards and complies with ASME B18.5 and SAE J429 manufacturing specifications. The product meets critical regulatory requirements including RoHS 3 (2015/863/EU) compliance and REACH (EC 1907/2006) compliance, ensuring environmental responsibility and material safety. Manufacturing controls guarantee consistent 5/16"-18 UNC coarse thread geometry and proper square neck dimensions (0.19" length × 0.32" width) for reliable anti-rotation performance in standard applications.