Zinc Coach Screws
Classic zinc plated coach screws for heavy-duty timber and masonry fixing.
Zinc Plated Coach Screws for Structural Timber Fixing
Zinc plated coach screws are a traditional heavy-duty fixing for timber-to-timber applications and for securing ironmongery to timber. When used with a suitable nylon plug, they can also be installed into masonry.
Manufactured to DIN 571, these screws feature a coarse deep thread for strong pull-out resistance and a part-threaded shank designed to clamp materials tightly together.
Thread length is approximately two-thirds of the overall screw length.
For example, a 100mm screw has roughly 60mm of thread.
Zinc plating provides corrosion resistance for indoor and sheltered outdoor use.
Typical Applications
Zinc coach screws are commonly used for:
- Joining structural timbers
- Securing brackets and metal plates to timber
- Fence posts and sleepers (sheltered use)
- Timber framing and landscaping
- Masonry fixing when paired with a nylon plug
They are ideal where strength and mechanical fixing are more important than speed of installation.
How to Install Coach Screws
For best results:
- Drill a pilot hole — essential in hardwood and recommended in most timbers
- Pilot size should be approximately 1–2mm smaller than the screw’s core diameter
- For hardwood, drill roughly 75% of the screw’s diameter
- Drive using a spanner, socket, or impact wrench
- Avoid overtightening to prevent splitting
When fixing into brick or block, use a correctly sized nylon plug.
Zinc vs Exterior vs Stainless – Which Coach Screw Should You Choose?
Different site conditions require different levels of corrosion protection. Choosing the correct finish helps prevent premature rusting, staining and structural failure.
Quick Comparison Guide
| Finish | Best For | Environment | Why Choose It |
|---|---|---|---|
| Zinc Plated | General construction, internal timber, sheltered structures | Dry indoor or protected outdoor areas | Cost-effective and suitable for most structural timber jobs where exposure is limited |
| Exterior Green Coated | Fencing, pergolas, landscaping, treated timber | Outdoor environments with regular moisture | Multi-layer coating offers improved corrosion resistance for external use |
| Stainless Steel | Coastal projects, exposed builds, corrosive timbers | Wet, exposed or coastal environments | Material-based corrosion resistance with no coating to wear away |
How to Decide
- Working indoors or in a dry shed? → Zinc is normally sufficient.
- Building a fence or pergola outdoors? → Exterior Green offers stronger weather protection.
- Near the coast or using oak/cedar? → Stainless steel is the safest long-term option.
Choosing the right finish reduces callbacks, staining and premature fixing failure.


