Silicon Bronze Fasteners
The traditional boat fastener — strong, non-magnetic, and made for saltwater. Quoted per order, confirmed before you pay.
Why silicon bronze?
Silicon bronze is a copper alloy — typically about 96% copper, 3% silicon, and 1% zinc — sold in alloys such as C65100 and C65500. It is the fastener wooden-boat builders have trusted for generations: highly resistant to saltwater corrosion, strong enough for structural planking and framing, non-magnetic, and kind to timber. Unlike brass, which is weaker and corrodes faster in saltwater, silicon bronze holds up below the waterline and in wood that stays wet.
Bronze is softer than stainless steel. Do not over-torque it, and do not use a power driver at full force on small bronze screws without testing first — a snapped bronze screw in hardwood is a difficult extraction. If your job needs maximum hardness rather than corrosion performance, 316 stainless may be the better call, and your quote request can say so.
Fastener families in silicon bronze
- Wood screws — flat-head Frearson-drive screws for planking, decking, and trim, plus square-drive options. Give gauge (number) and length.
- Machine screws — slotted round-head and flat-head screws for machinery, panels, and assemblies.
- Hex bolts and hex cap screws — for through-bolting frames, knees, and hardware, with matching bronze nuts and washers.
- Nuts — hex finish nuts and low-profile jam nuts (about two-thirds the thickness of a standard nut) for locking or tight spaces, tightened against a second nut by the double-nut method.
- Washers — flat, finish, and countersunk washers in matching bronze.
- Boat nails — annular-thread silicon bronze nails for planking and framing.
How to specify a silicon bronze fastener
| Field | Example (wood screw) | Example (bolt) |
|---|---|---|
| Fastener type | Wood screw, flat head | Hex bolt |
| Size | #10 gauge | 3/8 inch diameter |
| Thread | Coarse thread | 16 threads per inch |
| Length | 2 inches | 3 inches |
| Head / drive | Frearson drive | Hex head, external hex |
| Quantity | 50 pieces | 12 pieces |
Choosing by job
- Wooden boat, below the waterline: silicon bronze is the traditional and safest choice — it resists crevice corrosion when enclosed by wood.
- Docks, piers, and coastal woodwork: silicon bronze wood screws and bolts hold up in constant wet and salt air without staining the timber.
- General saltwater hardware and metal assemblies: consider 316 stainless instead — harder, and usually the practical choice outside wooden hulls.
- Mixing metals: avoid pairing highly dissimilar metals in saltwater without isolation — dissimilar metals in an electrolyte can drive galvanic corrosion of the less noble one. If your assembly mixes bronze, stainless, and aluminum, say so in your quote request and the specification will be checked before anything is confirmed.
Common questions
Silicon bronze or 316 stainless — which should I choose?
For wooden boats, especially below the waterline, silicon bronze. For general saltwater hardware and metal assemblies, 316 stainless is usually the practical choice. Describe the job in your quote request if you are unsure.
Is silicon bronze stronger than brass?
Yes — harder, stronger, and far more resistant to saltwater corrosion. Brass is not a substitute for bronze in marine work.
Is anything on this page in stock?
No. Every order is sourced to your exact specification and confirmed before payment. Nothing here is a stock list.
How much do silicon bronze fasteners cost?
Prices are quoted per order against current supplier availability for your exact specification. Request a quote and you will get a written price before you pay anything.