Welcome to your go-to guide on coach screws and coach bolts, brought to you by Allfast Tewkesbury, your trusted UK-based hardware store. Whether you're in the trade or a DIY enthusiast, understanding the basics and nuances of these fasteners can make a significant difference in your projects. Let’s dive into the world of coach screws and bolts.
What are Coach Screws and Coach Bolts?
Coach Screws: These are large, heavy-duty screws designed with a hexagonal head, intended for securing metal to timber or for fastening heavy timbers. Their sharp points and robust threaded bodies offer strong holding power in wood and similar materials.
Coach Bolts: Also known as carriage bolts, they have a round head and a square neck immediately beneath it. When inserted into wood, the square neck prevents the bolt from turning, ensuring a tight fit. They're primarily used for fastening metal to wood or wood to wood.
Uses
Both coach screws and bolts find their applications in various construction and assembly projects. They are ideal for:
Decking and outdoor structures
Fencing and gates
Timber frame construction
Securing heavy machinery
Joining metal to wood structures
Available Thread Sizes and Lengths
Thread sizes for coach screws typically range from M6 to M12 in diameter, with lengths varying from 30mm up to 200mm or more, catering to different project requirements.
Coach bolts come in diameters starting from M5, with lengths extending from 20mm to over 300mm for larger construction needs.
Standards
These fasteners adhere to specific standards ensuring quality and uniformity. In the UK, common standards include:
BS EN ISO 898-1 for mechanical properties of fasteners made of carbon steel and alloy steel.
BS EN ISO 3506 for corrosion-resistant stainless steel fasteners.
Coach Screws Fastening Mechanism
Coach Screws: Driven into pre-drilled holes using a wrench or socket for high torque application.
Coach Bolts: Inserted through pre-drilled holes and fastened with a nut. The square neck beneath the head grips into the wood, preventing rotation during tightening.
How to Use a Coach Screw
Pre-drill a pilot hole slightly smaller than the screw diameter.
Position the screw on the material.
Drive the screw into place using a socket or wrench, ensuring it's tightly secured.
Material Composition
Coach screws and bolts are usually made from:
Carbon Steel: For standard applications requiring strength.
Stainless Steel: For outdoor or corrosive environments, offering durability and resistance.
Galvanized Steel: Provides additional corrosion resistance for exterior applications.
Choosing the Correct Size
Selecting the right size depends on:
The weight and type of materials being fastened.
The thickness of the materials.
The environment (indoor or outdoor) where they will be used.
Ensure the length is sufficient for the screw or bolt to penetrate and secure the materials together effectively.
Quick Tips for Easy Application
Always use the correct size pilot hole to prevent wood splitting.
For coach screws, using a lubricant can ease the installation process.
Ensure you're using the appropriate tools for driving the screws or tightening the bolts.
Regularly check and retighten if necessary, especially in structures exposed to vibration or movement.
Conclusion
Allfast Tewkesbury is committed to providing high-quality fastening solutions for both tradespeople and DIY enthusiasts alike. Understanding the fundamentals of coach screws and bolts ensures that you select and use the right fastener for your project, guaranteeing durability and strength. For any further assistance or to explore our extensive range of products, visit our store or contact us directly on 01684 273344.