What are Coach Bolts?

Coach bolts, known for their robust and versatile nature, are a staple in precision engineering. These bolts feature a domed or countersunk head and a square section under the head, allowing them to grip and sink into a material to prevent turning during installation.

Typically used in wood-to-metal or wood-to-wood applications, coach bolts are renowned for their strength and reliability. They can also be used in standalone metal when a square recess is already provided or in plastics and composites similar to wood.

How Coach Bolts Work.

The practicality of coach bolts shines across various industries, from fabrication to furniture manufacturing. These bolts are ideal for creating strong joints in wood, offering a secure hold in both structural and decorative applications.

When using coach bolts for wood in construction, they're championed for timber framing or attaching ironwork to wood. In furniture making, their aesthetic appeal and strength make them a top choice for robust, long-lasting joinery.

Materials For Coach Bolts.

Accu offers stainless steel coach bolts in both A2 and A4 grades, ensuring durability and resistance to corrosion. A2 stainless steel is a popular choice for indoor applications due to its balance of strength and corrosion resistance. A4 stainless coach bolts however, with their higher chromium and molybdenum content, are ideal for harsher environments, like marine applications and can withstand much higher tolerances for corrosion.

If you're searching for black coach bolts, additional finishes like AccuBlack chemical blackening provide an aesthetically pleasing matte black finish that can seamlessly integrate into blacked-out or stained wooden workpieces.

Optionally, AccuLock thread locking patches further enhance their utility, providing extra protection against the nuts you apply loosening and ensuring a secure fit.

Coach Bolt Sizes and Types.

Our range of coach bolt sizes spans sizes from M5 (5mm) to M16 (16mm) in thread size, and lengths including our smallest 25mm, middle ground 150mm coach bolts to our longest 300mm, catering to a wide array of project requirements.

If our on-site availability doesn't quite suit your exact requirements, Accu prides itself on custom manufacturing so you can get the right spec of component that you need.

For a comprehensive installation solution, consider exploring our range of accompanying nuts and washers.

FAQs.

Q: What is a coach bolt used for?.

A: Exterior coach bolts are primarily used to securely join wood to metal or wood to wood, often in construction and furniture making due to their strength and ease of installation.

Q: What is the difference between a carriage bolt and a coach bolt?.

A: Both carriage and coach bolts are the same component with a smooth, rounded head with no drive tool slot. There is often confusion between coach bolts and coach screws which our article compares and also included the differences between lag bolts too. 

Q: Do you need washers with coach bolts?.

A: Typically, washers are only required on the nut side as the large domed head provides enough support. Washers can be used however the internal diameter needs to make sure that it doesn't interfere with the square neck nature of these fasteners.

Q: Do you hammer coach bolts?.

A: No, they are not designed to be hammered in in a traditional sense. They should be inserted into pre-drilled holes, once the square neck begins to interact with the material, they can be lightly tapped to provide enough bit to then be tightened with a wrench or socket.

Q: Are coach bolts self-tapping?.

A: No, their threads are not self-tapping. Pre-drilled holes along with nuts and washers are necessary for their installation to ensure a secure and proper fit.

 

Bespoke Coach Bolts Manufacture.

High precision, bespoke manufacture of Coach Bolts to customer specification. State of the art facilities specialising in both small batch prototyping and large scale manufacture.

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