Has Stainless Steel Met Its Match?

When installing fasteners in any outdoor environment, a primary consideration needs to be how the fasteners will be engineered for corrosion resistance. This is an even more important question in the case of very wet or extreme conditions, such as in coastal environments or geographies where rainfall and snow is heavy. The traditional approach to these situations was to encourage the use of stainless steel fasteners, but a variety of coatings and treatments are changing that perception, often offering added strength and cost savings while retaining the corrosion resistance of stainless.

DURA-CON Corrosion Resistant Fasteners employ a three layer coating system that consists of an inorganic zinc-rich first coat and an aluminum-rich organic second coat. Friction modifiers are integrated into the topcoat, resulting in repeatable torque tension characteristics during assembly. Grade 5 bolts are stronger than A307 zinc, hot dip galvanized or 300 series stainless steel bolts. DURA-CON coating provides superior corrosion resistance; withstanding 1,500 hours of Salt Spray per ASTM B-117, at a cost significantly lower than stainless steel fasteners.

Strong-Point Fasteners has a new coating called Strong Shield, which they claim to be 50% less expensive than stainless steel and more than 40 times more corrosion resistant than zinc. Strong Shield consists of four layers: a metallic zinc layer, a hex-chromium passivation, a layer of functional nano coating used as a sealer, and a high-grade anti-corrosion chemical conversion film. These fasteners can withstand 1,000 hours of Salt Spray - not as high as DURA-CON Fasteners but still very good for corrosive environments.

Many products from Elco Fasteners are coated with Stalgard, an environmentally friendly corrosion resistant finish that’s free from chromates and silicates and any processes, such as electroplating, that might induce hydrogen embrittlement or structural failures. While fasteners coated in Stalgard max out at 1,000 salt spray hours as well, this coating comes in a variety of colors, making them a good choice where particular aesthetics or needs for identification come into play.

So, has stainless steel met its match? The answer depends on what features of a fastener are most important to you, and what specifications you’re trying to meet. If you’re looking for an alternate to stainless steel fasteners, contact Mudge Fasteners at (800) 634-0406 to get the information you need.