How to choose coastal hardware that resists salt-air corrosion

Map the real exposure

An interior handle in conditioned space does not face the same salt, moisture and ultraviolet exposure as an exterior gate. Distance from the shore is only a first screen. Wind direction, surf or sheltered water, humidity, direct spray, rain washing and the time a surface stays wet all change the corrosion load.

ASSDA notes that sheltered or rain-shadowed surfaces can be especially vulnerable because salt remains on them. Record whether the fitting is outdoors, under an eave, in a splash zone, near a pool, or routinely washed by rain before comparing materials.

Treat 316 as a starting point, not a promise

“Stainless steel” names a family of alloys, not a guaranteed coastal performance level. ASSDA’s Australian guidance says grade 316, or equivalent corrosion resistance, should be the minimum within five kilometres of surf. It also says splash zones, unwashed areas, rough surfaces and severe marine atmospheres may require higher-alloyed grades such as duplex or super grades.

Grade is only part of the answer. Surface roughness, crevices, weld treatment, fabrication contamination and drainage affect whether salts collect and whether the protective passive layer can perform. Do not turn an Australian distance guide into a universal building-code rule; use it to ask a local specifier for the project’s exposure class and required service life.

Specify the whole assembly

A corrosion-resistant hinge with ordinary screws still has an ordinary-screw failure point. Ask for the exact alloy or coating of the fitting, screws, anchors, washers and concealed parts—not only the visible finish.

Connections also meet timber, masonry, sealants and other metals. FHWA guidance shows that preservative-treated wood systems can require hot-dip galvanised or stainless fasteners. A qualified local professional should check compatibility, loading, code requirements and whether the detail creates a crevice or water trap.

• Match the life of every fastener and fitting.
• Keep joints free-draining and inspectable.
• Separate incompatible materials where the specification requires it.
• Confirm how cut edges, welds and damaged coatings are treated.

Buy the maintenance path

Stainless steel is low maintenance, not maintenance free. ASSDA recommends light, regular washing where natural rain washing is insufficient and warns against chloride- or bleach-containing cleaners. Follow the product maker’s cleaning instructions rather than improvising a chemical treatment.

Before purchase, ask for the installation method, cleaning interval, warranty exclusions, inspection points and replacement availability in writing. Photograph the installed condition, inspect before the wet or storm season, and respond to staining, looseness or coating damage before concealing the evidence.