Carriage Bolts Three Eighths Inch Sixteen Threads Four Inch Length A307 Grade Zinc Plated Steel Smooth Round Head With Square Shoulder 25 Pack Great For DIY Projects Like Furniture Decks And Construction Where Protruding Heads Do Not Bite

3/8 in Coarse Carriage Bolts, 4 in, zinc plated, 25-pack
✔️ 3/8 dia, 4 in long, UNC-2A coarse thread, zinc plated

These carriage bolts are a zinc-plated option with a smooth rounded head and square shoulder, designed for projects where exposed bolt heads could snag or injure. Each bolt is 3/8 inch (9.5 mm) diameter and 4 inch (101.6 mm) long, ideal for furniture, decks, docks, and outdoor builds where a clean look matters and the head sits flush or below the surface.

✅ Diameter 3/8 in (9.5 mm), length 4 in (101.6 mm), UNC-2A coarse thread
✅ Smooth rounded head with square shoulder for anti-rotation
✅ Zinc plated finish for outdoor use
✅ Pack: 25 bolts; nuts & washers not included

💡 What is a carriage bolt used for in outdoor furniture and deck projects?

- handy for items where a smooth rounded head is preferred and won't snag skin - great when a square shoulder locks in place while you tighten a nut - requires nuts and washers of matching diameter for a secure fit in wood or metal