Best Flat Head Carriage Bolts of 2025

The OUSCHR Carriage Bolt Kit includes four 5/16-18 x 3" carriage bolts, hex nuts, and flat washers, ensuring you have everything needed for secure fastening. With a thread diameter of 5/16 inch and a length of 3 inches, these bolts provide excellent strength for heavy applications. Made from 304 stainless steel, they offer great corrosion resistance and durability, making them reliable for outdoor use. The dome-shaped head and square neck design enhance security and self-locking capabilities, providing peace of mind in your projects.

The National Hardware Carriage Bolts are designed for versatile use on wood or steel surfaces. Their unique design prevents spinning during installation and tightening, making the process much easier for you. You can tighten these bolts without needing access to both sides of the door, which adds convenience, especially in tight spaces. These bolts are specifically tailored for wood or steel garage doors, ensuring a secure fit and reliable performance for your projects.

The sourcing map Carriage Bolt is crafted from 304 stainless steel, ensuring high hardness and exceptional corrosion resistance, making it perfect for wet environments. With a thread diameter of 1/4-inch and a length of 3/4-inch, this bolt provides a secure and reliable fit, especially when used in square holes. Its round head and square neck design, compatible with hex nuts and flat washers, enhance stability in fastening. Ideal for various applications, you can confidently use it to fix metal to wood in both indoor and outdoor projects.

The Glvaner Carriage Bolts offer a comprehensive set, including six M10-1.5 x 100mm carriage bolts, hex nuts, and flat washers. The coarse thread and robust construction provide excellent strength and stability for your projects. The round head design and square neck ensure a secure fit, making them self-locking when placed in square holes. Made from 304 stainless steel, they offer superior corrosion resistance compared to standard fasteners, making them ideal for both indoor and outdoor use.

The sourcing map Carriage Bolts set includes 12 robust stainless steel carriage bolts, along with matching hex nuts and flat washers. Made from 304 stainless steel, these bolts are highly reliable and resistant to corrosion, ensuring they last in various conditions. Their unique design features a round head and square neck, which prevents rotation during installation, making it easier for you to secure your projects. Additionally, the head's design allows for a clean finish, as it can remain hidden during use to deter disassembly.

The LBY Carriage Bolts Set includes eight square-neck carriage bolts that measure 5/16-18 x 3 inches. Made from durable carbon steel with a black finish, these bolts are ideal for various applications, including furniture assembly. Their 5/16 inch diameter and 3-inch length provide the strength needed for secure connections. You will find them particularly useful for beds, chairs, and sofas, making your furniture projects straightforward and reliable.

The sourcing map Carriage Bolt Kit includes eight carriage bolts, washers, and nuts, all made from low carbon steel for enhanced strength. With a round head and square neck design, these bolts ensure a secure, self-locking fit, making your projects more reliable. Their versatile size makes them suitable for various applications, whether you are fixing metal to wood or working on DIY projects around the home or office. You can count on these bolts to provide robust structural support in a range of environments.

The M8 Carriage Bolt is designed with a flat dome head and a square neck, preventing rotation once fitted. Ideal for wooden constructions, these stainless steel bolts provide higher tensile strength, making them suitable for exterior applications where moisture exposure is a concern. You will find that the cup square design allows for easy fastening with a hexagon threaded nut, ensuring secure installation. Additionally, accurate measurement from the head is essential to achieve the correct length for your projects.

The SHUNCHG Coach Bolts set offers a versatile selection, including 20 carriage bolts and 20 hex flange nuts, making it perfect for various applications. Crafted from premium carbon steel, these bolts and nuts are suitable for both indoor and outdoor use, even in humid environments. Their innovative design features flat heads and square shoulders, which help prevent loosening during use. Additionally, the knurled flange nuts ensure a secure hold, providing you with peace of mind for all your fastening tasks.

The Etomvoop Bolt and Nut Set offers a secure fastening solution with its round head design and square neck, ensuring a self-locking fit in square holes. You can rely on the high-quality 304 stainless steel materials for excellent corrosion resistance, making it perfect for outdoor use. This fully mounting kit includes 30 carriage bolts, nuts, and flat washers, providing ample supply for your projects. With precise dimensions, these bolts are compatible with various applications, making them ideal for wood-to-wood and wood-to-metal fastening.