8.2 Stainless Steel

Stainless steel is created when other metals are added to steel to make an alloy. The composition of the alloy determines its corrosion resistance, temperature resistance, and hardness and denotes the stainless steel type. Not all types of stainless steel have the same corrosion resistance, and some types are preferred over others in saltwater applications. Several connector manufacturers produce the most commonly used connectors in a stainless steel option. Stainless steel is resistant to corrosion in salt air, and it usually lasts longer than most other materials, even in the most corrosive oceanfront situations.

To eliminate the potential for galvanic corrosion, stainless steel connectors must be attached with stainless steel nails when separate fasteners are needed; otherwise, corrosion will be accelerated on the less corrosion-resistant metal and can dramatically reduce its lifespan (see Figure 7). In coastal applications, stainless steel should be Type 304 or Type 316. Type 316 is more resistant to corrosion and should be used for stainless steel metal connectors. Some fasteners are fabricated from Type 410 stainless steel, which has more corrosion resistance than galvanized bare steel but less than Type 316 stainless steel.

Stainless steel is tougher than normal carbon steel, which means that stainless steel connectors are more difficult to fabricate. Also, stainless steel tends to be more expensive than carbon steel and galvanized steel. When considering upgrading from galvanized fasteners and connectors to stainless steel, designers, contractors, and building owners in coastal areas should compare the cost of stainless steel connectors to G185 galvanized connectors, not to G60 and G90 galvanized connectors, which are not recommended in coastal areas. Furthermore, the reduced maintenance/replacement/labor life-cycle costs when using stainless steel should be considered when specifying connectors. See Section 9.2.2 for further details.