Exterior Silver Carriage Bolts with Washer & Nut

About Exterior Silver Carriage Bolts

Exterior silver carriage bolts, also known as cup square bolts, are designed for clamping timber or attaching ironmongery to timber where enhanced corrosion resistance is required. The domed head provides a neat, finished appearance, while the square anti-spin shoulder beneath the head locks into the timber to prevent rotation during tightening.

Each bolt is supplied with a matching hex nut and Form A washer, providing a complete fixing solution. The washer helps distribute load across the timber surface, while the nut allows secure tightening from one side.

Designed for Long-Term External Use

These carriage bolts are coated with a patented multi-layer silver organic corrosion-resistant plating. This finish is designed to withstand up to 1,000 hours salt spray testing, making it suitable for exposed and demanding external environments.

The exterior silver coating provides extended protection compared to standard plated fixings and is well suited to outdoor timber construction where long service life is required.

Typical Applications

Exterior silver carriage bolts with washer and nut are commonly used for:

• Decking subframes and outdoor timber structures
• Fencing, gates and pergolas
• Landscaping and garden buildings
• Fixing ironmongery to external timber

The domed head creates a low-profile finish, making these fixings suitable for visible installations.

Choosing the Right Bolt Size