Harbor & Hull makes deck hardware for working boats and premium recreational craft. Their cast-stainless cleats looked good on the shelf but were pitting, staining, and seizing at the fasteners after a season in salt water — and on a working vessel, deck hardware that corrodes is both a safety issue and a warranty one.
Salt water finds every weakness
A cleat takes real load — dock lines, anchor rodes, tow bridles — so it has to be strong. But the harder test is chemistry: constant salt spray, immersion, and galvanic coupling with whatever it's bolted to. Harbor & Hull's stainless castings were suffering crevice corrosion at the fastener holes and staining that customers read as cheapness.
They wanted hardware that ages gracefully in exactly the environment that's hardest on metal.
Bronze is the traditional answer for a reason
Silicon bronze has been the marine metal of choice for generations because it resists salt-water corrosion, handles galvanic coupling far more gracefully than many stainless grades in crevice conditions, and takes a beautiful, durable finish. Sand casting suits the low-to-moderate volumes and generous shapes of deck hardware.
Switching from stainless to a proper marine bronze was the fix — the same part, cast in a material actually suited to the sea.
The part we built
We sand-cast the cleat base in C875 silicon bronze, cast to a CT7 tolerance grade, then tumbled and polished it to the finish marine buyers expect. The bronze resists the salt-water corrosion and crevice attack that had been pitting the stainless, and it develops an even, attractive surface rather than blotchy staining as it weathers.
We handle the casting and finishing in-house, so Harbor & Hull gets a finished, ready-to-sell cleat base.
Hardware that ages well
A season in the same salt service that had been pitting the stainless left the bronze cleats sound at the fastener holes and evenly finished, ending the corrosion warranty claims. Just as important for a premium brand, the hardware looks better as it ages instead of worse.
Sometimes the modern material isn't the right one. For deck hardware, bronze earned its reputation the hard way.
“We tried to modernize with stainless and the sea won. Back in silicon bronze, the cleats hold up and actually look better with age.”
Tom Alvarez, Owner, Harbor & Hull Marine