Is all Stainless Steel the Same?

Is all stainless steel the same?


How do I decide and why are the prices so different?

Most stainless steel is not suitable for permanently immersed applications both fully or partially. Swim ladders left in the water or close to the water for long periods have a predictable short-term life.
Most stainless steel is not suitable for permanently immersed applications both fully or partially. Swim ladders left in the water or close to the water for long periods have a predictable short-term life.

In chandleries we see our customers apparently sweating choices when it comes to products made of Stainless Steel. Many of them do not have long experience in the Caribbean conditions and they see highly varying prices and wonder what is going on. 

Petovens-Pierre Louis, Sales Floor Manager at Budget Marine St Maarten
Petovens-Pierre Louis, Sales Floor Manager at Budget Marine St Maarten

The word “stainless steel” is an unfortunate part of the English language because it is not steel and not stainless.  It does not suffer surface corrosion very much, but it does suffer electrolysis which is a sort of degeneration from the inside out. Stainless Steel is actually an iron based alloy containing around 11% chromium which creates the non-corrosive properties.

Stainless steel differs from regular steel in that it fails from the inside. The failure is sudden and catastrophic and cannot be easily anticipated with the naked eye. Which is why we carry some products purposely in steel because they are in applications where the cosmetics are less important, but the functionality is critical (e.g. hose clamps for exhausts).

Stainless steel varies enormously in quality. The common US certified types are 304 and 316.  Most stainless is 304 however the 316 is significantly better but also higher in price. To make matters worse, the certification numbers do not cover all aspects of the quality. Also note that a great deal of stainless steel comes with no type number at all. At the other end of the scale there is an expensive French manufacturer who specializes in the highest quality. Their product is seldom or never the source of failure. I would not put anything else on my personal boat.

The most important issue is to determine where the item is going to be used. You do not need the top quality for the hinges on your galley cupboards but there are other places where you certainly do need the superior quality.  

Do you need the quality for cosmetic reasons or for functional reasons? When it is cosmetic the stainless can retain its looks for much longer by “passivation” which consists of a type of polish that requires some build up. Stainless steel that is cosmetically significant will require regular cleaning and surface treatment.

Most stainless steel is not suitable for permanently immersed applications both fully or partially. Swim ladders left in the water or close to the water for long periods have a predictable short-term life.

NOTE: Stainless steel anchors and chain are the greatest example of an unsuitable long-term choice. They would make sense on a day boat where the immersion is for short periods but not on a long-term basis. Of course, stainless shackles used on ground tackle make no sense, this just creates risk and expense.  

Please send in Questions for the Experts to answer in a future issue to [email protected]

Robbie_Ferron
Sir Robbie Ferron founded the Sint Maarten Heineken Regatta and served as Caribbean Sailing Association President for nine years.