You may be like many of our solar customers with regard to new requests for stainless steel fasteners.
With the growing interest in mitigating future replacement costs many owners and developers are taking a long term view into consideration. In short they are investing wisely in an attempt to ‘see around the corner’ thus avoiding a dilution in quality- especially but not limited to salt spray conditions.
The outcome is many RFP’s have increased their requirements for stainless steel fasteners- some in metric, some English and in certain cases a combination of both.
Reducing the Confusion
The next question that often surfaces is what are marine grade fasteners? In several cases that we have seen many feel that stainless is stainless regardless of the geographic location of their installation.
To eliminate this misunderstanding I have outlined a basic definition below. This will help you as you source the best option to support your fastener strategy. Both 304 and 316 SS are considered austenitic stainless steels which contain about 18% chromium and 8% nickel.
Type 304 Stainless (18-8)
Chromium 18.00/20.00%, Nickel 8.00/10.50%
Type 304 stainless has always been the most economical stainless available and has been the industry standard for the level of corrosion resistance and strength required.
Type 316 Stainless is molybdenum bearing austenitic steel with increases percentages of nickel and capable of adding 2.5 to 5 times the corrosion resistance over plain 304 Stainless. It is more resistance to pitting corrosion than typical 18-8 alloys.
A Closer Look
Type 316 SS contains almost the same amount of chromium but is formulated with 10-14% more nickel, and 2-3% molybdenum. The addition of molybdenum provides extra corrosion resistance which is a plus in heavy salt spray or corrosive environments.
As you work to get it right for your organization and customer, I hope the above has been helpful as you work to differentiate your offering and execute your fastener strategy.