Diall M8 Coach Bolt & Nut - Pack Of 5
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Product Information
Full details
This guide is for DIY enthusiasts and builders needing reliable fasteners for timber projects. The key benefit is the durable, zinc-plated carbon steel construction ensuring strength and corrosion resistance for secure joints. A caveat is their specific recommendation for timber, limiting their use on other materials. This pack of five M8 coach bolts and nuts offers a convenient solution for various assembly tasks, featuring a 120mm length and partial threading for effective material grip.
All features
| Brand | Diall |
|---|
Extended Product Information
FAQs
What is a coach bolt and nut used for?
A coach bolt and nut system is commonly used for joining wooden components or for applications where a smooth, flush finish is desired on one side. The square neck under the bolt head prevents it from turning, allowing for single-handed tightening of the nut.
Can these bolts be used on metal?
These specific coach bolts are recommended for timber. While they might technically fasten metal, the partial threading and design are optimized for wood. For metal applications, consider bolts specifically designed for metal.
What size drill bit should I use for the M8 coach bolt?
For an M8 bolt, you typically need a drill bit slightly larger than the bolt's diameter, usually around 9mm or 10mm, to allow for easy insertion. Ensure the hole is not too large, as the square neck needs to seat properly.
How much threading is on the M8 bolt?
The M8 coach bolts in this pack have approximately 22mm of partial threading.
Are these bolts suitable for outdoor use?
Yes, the zinc plating provides good resistance to corrosion, making them suitable for many outdoor applications, especially when used with timber. However, prolonged exposure to harsh weather may eventually cause rust.
What does 'cup square' mean in relation to coach bolts?
'Cup square' refers to the shape of the bolt head, which has a slightly rounded top (cup) and a square neck underneath. This square neck is designed to fit into a corresponding square recess in the material being fastened, preventing the bolt from rotating.
Troubleshooting
Bolt spins when tightening the nut.
Ensure the square section of the coach bolt head is properly seated in a square recess or that the timber is dense enough to hold it firmly. If the hole is too large, consider using a washer behind the bolt head or shims.
Nut does not screw on smoothly.
Check for cross-threading or debris in the nut or on the bolt threads. Clean the threads or try a new nut if damaged.
Rust or corrosion observed.
While zinc plated, prolonged exposure to harsh elements can cause rust. Clean the affected area and consider applying a protective coating or replacing the fastener if significant damage has occurred.
Bolt length is insufficient for the combined thickness of materials.
This pack contains only 120mm bolts. For thicker materials, consider purchasing longer bolts or using alternative joining methods.
Pros and Cons
Pros
- Constructed from durable carbon steel for strength.
- Zinc plating offers good corrosion resistance.
- Partially threaded design provides secure fastening on timber.
- Generous 120mm length is suitable for thicker materials.
- Comes in a practical pack of five for immediate use.
Cons
- Primarily recommended for use on timber only.
- M8 diameter may not be suitable for all applications requiring larger fasteners.
- Partial threading limits the overall adjustment range compared to fully threaded bolts.
Setup, Compatibility & Care
Setup:
- Drill Holes: Drill appropriately sized holes through the materials you wish to join. The hole diameter should be slightly larger than the M8 bolt diameter (typically around 9-10mm) to allow for easy insertion.
- Insert Bolt: Pass the coach bolt through the aligned holes. Ensure the square section of the bolt head sits snugly in the square recess created by the coach bolt's design when inserted into the timber. This prevents the bolt from spinning while tightening the nut.
- Attach Nut: Screw the M8 nut onto the threaded end of the bolt.
- Tighten: Use appropriate wrenches or spanners to tighten the nut securely. Hold the bolt head stationary if it attempts to spin.
Compatibility:
- Material: Primarily designed and recommended for use with timber or other soft wood materials.
- Diameter: Compatible with M8 nuts and washers.
- Applications: Suitable for general DIY projects, furniture assembly, outdoor structures, and timber framing.
Care:
- Cleaning: Wipe clean with a dry or slightly damp cloth. Avoid abrasive cleaners.
- Storage: Store in a dry environment to maintain the integrity of the zinc plating and prevent corrosion.
- Inspection: Periodically inspect for signs of rust or damage, especially if used in exposed conditions.