The authoritative public forum
  for Metal Finishing since 1989
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Stainless steel on an outdoor grill

I am planning to purchase a outdoor gas grill. A recent Consumer Reports magazine suggested taking along a magnet to "test" the stainless. A better stainless, i.e., less subject to corrosion would be non-magnetic. Is this a reasonable test?

Thomas Cherek
home owner - Waukesha,Wisconsin
2005

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"Stainless Steel for Design Engineers" on AbeBooks or Amazon (affil links) The 300 series stainless steels are non-magnetic. They have good corrosion resistance, and will last almost forever, except for the heated parts, which will embrittle and fall apart after a few years. I'd rather have a grill with heavy cast aluminum case and porcelain enameled grills and burners. Jeffrey Holmes, CEF Spartanburg, South Carolina A stainless steel that is non-magnetic is usually higher in levels of chromium and other metals that are not ferrous, thus non-magnetic. Some stainless steels are magnetic and have good rust resistance qualities, there are a lot of qualifiers and different tests for checking the grade of stainless steels (acids, Rockwell hardness, spray test, etc). Stainless is not going to be the end all to your corrosion problems, it won't visibly rust, but it will have problems with long stints at high temperatures. Stainless steels are work hardened, in other words for the stainless to get hard it needs to be shot peened, rolled, or stressed in some way. Heat it up, even at low temperatures (700 deg F sometimes), it will slowly lose it's temper and show wear quite easily. But for a quick check for buying a grill? The magnet will work fine. You have other options as well, standard high temp. paints have gotten more durable and are a viable option for an outdoor grill. Cast iron holds up for decades if treated properly (think those outdoor grills you see at campgrounds and parks). Ceramic and masonry will last a lifetime of frequent grilling, there are some portable ceramic grills available that are wonderfully designed and cannot rust. Hopefully I've given you some food for thought. Good luck with the grilling come spring. Marc Banks Blacksmith - Shiloh, North Carolina "Stainless Steels" by ASM on AbeBooks or Amazon (affil links) Lots of alloys, with lots of variation in corrosion resistance, are non-magnetic; therefore your magnet test would be of limited use (I would suspect). That, however, is just the beginning of it though: there are a lot of different factors involved in determining the quality of any given part and the likelihood that it will rust, alloy is just the start. There is also method of passivation, and the amount of care taken during manufacture to avoid hi-corrosion factors (I could name more if we were talking about aluminum, but stainless steel isn't really my specialty). And, the likelihood of the stainless rusting or not is in no way a guarantee of the quality of the grill as a whole. As Ted (the moderator) has said multiple times - ultimately there is just too much involved and too little information known or available about any given product for a consumer (whether a member of the general public or a finishing expert) to make an informed decision. What it all comes down to is picking a manufacturer with a good reputation and hoping they did everything correctly. Incidentally, consumerreports.org is a good way to decide which manufacturers have a good rep and which don't and a subscription to their website is fairly cheap. Good luck! Jim Gorsich Compton, California, USA Generally, yes. The martensitic, precipitation hardening, and ferritic stainless steels are the ones that are magnetic. They have less corrosion resistance than the standard 18-8 (chromium and nickel content, in %) austenitic stainless steels, which are not magnetic in their annealed condition. The austenitic grades CAN become magnetic when they are heavily cold worked- items like sheet and wire. They'll still have better corrosion resistance than the standard martensitic, precipitation hardening, and ferritic grades, but that's why I had to couch the answer with "generally" instead of a flat out "yes". Lee Gearhart metallurgist - E. Aurora, New York

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2005

Thanks for all the responses. It is really great to have people who "know" the science behind a product share their knowledge.
Since I wrote my first question I've seen several stainless grills after extended use. All showed signs of stains from heating. I've decided to go with a cast iron or aluminum grill with a brass or cast iron burner.
Thanks for all your help. Tom

Thomas Cherek
- Waukesha,Wisconsin

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Q. How can I easily check that my supplier is producing goods from 304 Stainless and not from other grades of stainless steel with less corrosion resistance

Rik Saunders
- Perth. WA, Australia
February 15, 2010

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Multiple threads merged: please forgive chronology errors :-)

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Protect stainless steel grill near the ocean

Q. Sir, I purchased a stainless steel Gas Grill for my outdoor kitchen. Living on the Atlantic ocean, I was told that I should SPRAY the grill with some sort of protective finisher. To protect against rust and corrosion, what do you suggest that I use to spray on the Grill, if anything. Incidentally, I did purchase a custom cover made for the Grill. I so value your advise; thank you for the response.

Dr. Betty Green
- Palm Coast, Florida, USA
July 30, 2012

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Outdoor kitchen and grill in 304 vs. 430?

March 24, 2015

Q. Hi all.. Kristoffer here.

Need your expert opinion on a product we are planning to sell.
We have been offered some outdoor kitchens and outdoor kitchens combined with a nice charcoal bbq.
All is made of stainless steel - and we can choose to have it made from either 430 or 304. I have read that 304 are more resilient to corrosion but 430 should be better at withstanding the heat from the grill. Is this correctly understood, or are even 304 a better material for a bbq?

The kitchens are made from 1,25mm thick steel (either 304 or 430). From producers we have been told that expected "life" of the kitchen if made in 430 should be around 15-20 years. How does this sound to an expert? :-)

If we choose to produce in 304 rather than 430 - any suggestion to how much longer we could expect the steel to withstand corrosion. It's outdoor kitchens, so we expect them to be outside without cover year around (in all kinds of weather).

Our difference in buying price between 430 and 304 are around 50 USD per product (around 10% of total price) In your opinion (10 % is not much) is it worth it to produce in 304 instead of 430?

Thank you so much for any help in this.
Best regards

Kristoffer Lauritsen
Buyer - Trelleborg, Scania, Sweden

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Stainless Steel as Infrared Plate in an Outdoor Grill

April 3, 2015

Q. Hello everyone. My apologies if this question was asked previously. I did a search and it did not come up.

I have an older outdoor grill that should last me a few more years. I wanted to use a stainless steel plate to create and infrared plate under the cooking grates. For those unfamiliar, an infrared plate in a grill is basically a thin piece of stainless steel that has tiny holes all along the surface of the sheet. It is inserted on top of the burner and under the cooking grate. It eliminates flare ups and supposedly creates an intense radiant heat around 800 °F.

I was thinking of purchasing a stainless steel sheet and drilling tiny holes along its surface to accomplish this effect in my grill.

1) What gauge of stainless steel would be best for this application? I was thinking 16 ga.
2) All the of the places I've searched list stainless steel sheets with a #2 finish or #4 finish. What is the difference? Are both food safe? Which would be better in this application?
3) Will the sheet warp or rust quicker under that kind of heat?

Any help would be appreciated. I'd like to get this done before May and in the safest and most durable way possible.

Thanks in advance.

Neil B [last name deleted for privacy by Editor]
- New Brunswick, New Jersey