Carriage Bolt, Washer and Nut – Exterior Green

About Exterior Green Carriage Bolts

Carriage Bolt, Washer & Nut – Exterior Green sets are designed for structural timber connections where strength, security and corrosion resistance are essential. Featuring a domed head and square anti-spin shoulder, these bolts provide secure clamping while preventing rotation during installation.

Each set includes a matching washer and hex nut, creating a complete fixing solution for timber-to-timber or metal-to-timber connections.

Finished with a green multi-layer exterior coating, these bolts are suitable for demanding outdoor environments and offer up to 500 hours salt spray resistance.

Key Features

• Domed head for neat finish and even load distribution
• Square shoulder prevents bolt spin during tightening
• Supplied with matching washer and hex nut
• Green exterior coating for outdoor durability
• Fully threaded up to 150mm, part threaded above
• DIN 603, DIN 934 and DIN 125-A compliant

Where These Carriage Bolts Are Used

Exterior green carriage bolts are commonly used for:

• Structural timber joints
• Fencing and gate construction
• Pergolas and garden buildings
• Sleepers and retaining structures
• Timber frames
• Fixing ironmongery to timber

They provide strong clamping force while maintaining a tidy external appearance.

Understanding the Components

• Domed Head
  Spreads load across the timber surface and reduces pull-through while maintaining a clean finish.
• Square Shoulder
  Bites into the timber as the nut is tightened, preventing rotation and allowing one-person installation.
• Thread Design
  Fully threaded bolts provide maximum engagement. Longer bolts are part threaded to improve clamping efficiency and reduce friction.

Exterior Green Finish – Why It Matters

The green exterior coating is a patented multi-layer plating system designed for outdoor timber applications. It offers strong corrosion resistance without requiring hot-dip galvanising and blends discreetly with treated timber.

Suitable for garden structures and external joinery, it helps prevent rust staining and thread degradation over time.

Carriage Bolt Size Guide

How to Install a Carriage Bolt

1. Drill a correctly sized clearance hole through the timber or steel component.
2. Tap the bolt through so the square shoulder engages with the timber.
3. Fit the washer and nut.
4. Tighten using a spanner or socket until secure, avoiding over-tightening in softer timbers.