Comparing stainless steels in cookware

A. He is correct in saying that 304 is better than 302, but only slightly. 18-8 is even better but not used that much. He is absolutely wrong about the aluminum leaching thru in any detectable quantity thru the 302 or 304.

Snake oil salesman. Buy from him at your own risk. I would not, but that is me.

A. 18-8 refers to a class of stainless steels including 302, 304, 316, 347 that have a chromium content of approximately 18% chromium and 8% nickel. They all have approximately the same corrosion resistance however the different alloys have different characteristics that make them easier to machine or offer more corrosion protection under different environmental conditions. 302 and 304 are frequently used interchangeably. The main difference is 302^³⁰⁴ has .08% carbon versus .15% for 304^³⁰². Additionally 304 generally contains 1-2% more chromium than 302. I would guess any differences in cookware would be minimal.

A. Dale Neff and Phillip Ooi almost got it right.

Both 302 and 304 are known as "18-8" stainless steels, as are several other of the 300-series stainless steels (300-series stainless steels are called "austenitic" stainless steels), the 18-8 referring to the "average" amount of chromium and nickel in their chemistries, and the min/max levels vary only slightly for the 302 (17-19 Cr) vs. 304 (18-20 Cr). .

However, 302-stainless is the alloy with the higher carbon content, not 304, and it should be noted, too, that these carbon contents are maximums only. Thus, 302-stainless has a maximum of 0.15 percent carbon, and 304-stainless has a max of 0.08 percent carbon (both alloys usually have less than their maximums). Because 304 stainless is able to control the carbon levels better, it is the most frequently used stainless alloy today, rather than 302.

Both of these stainlesses will perform very well in cookware, and one is not to be preferred over another from a metallurgical point of view as far as performance is concerned.

John Barile points up a common mistake many people make, namely that of believing everything they are taught. Obviously the salesman was saying what he was taught, and is a clear example of the blind leading the blind.

Take comfort in knowing that any stainless cookware you have at home is safe, does not allow food to leach through it, is highly corrosion-resistant, and should give you a lifetime of good service if not abused.

A. Hi, Julie. No, the reasoning is not correct, as you can see from the previous postings on the page. However, T316 is more corrosion resistant than T304 and the manufacturer may have been trying to make that point. Good luck.

Regards,

A. Hi John. All stainless steel can be corroded by salt eventually, although 316 is probably slightly more resistant. It would be extremely difficult to estimate what percentage of those molecules are ingested vs. poured down the drain as cooking water vs. scrubbed off by cleaning. I think the best thing to say is that pots tend to last decades with little visible wear, and hundreds of millions of people have had their food cooked in pots for their entire lifetime without any obvious issues. Plus, most of the material of the pots, including the iron and the chromium and the nickel, are essential micronutrients, not poisons.

Regards,

A. There is no difference in resistance to general atmospheric corrosion between Type 302 (UNS S30200) and Type 304 (UNS S30400). For fasteners that are cold formed (cold headed), there is a modified grade such as Custom Flo 302HQ from Cartech that includes 3-4% Cu for reduced work hardening & improved formability. The official designation is UNS S30430, and it has similar corrosion resistance to the other two grades. There is no substantial difference in the cost between 302 and 304 relative to alloying content, so any differences being quoted must be due to different manufacturing processes, suppliers, availability, etc.

A. Hi Pier. Although there is a type 316Ti titanium-enhanced stainless steel, to my knowledge there is not a 304Ti. When people use the phrase T304, it's probably just an abbreviation of "type 304" rather than a reference to titanium.

There is not a lot of titanium even in type 316Ti stainless -- not over 0.7% at the most. As for what exactly it does, you can see Allegheny Ludlum's datasheet on it .

Remember that companies generally want to induce you to buy their product, rather than to technically inform you. So the cookware manufacturer might even have picked a formulation on the basis of sales appeal (Titanium!) than on real technical advantage. Reading Allegheny Ludlum's discussion, I see no advantage to 316Ti which would both truly be significant and apply to cookware. But there is a lot more to quality than a recipe -- as a cook like yourself probably knows a lot better than the rest of us :-)

A charcoal study on paper by Renoir is significantly more artistic than the finest oil on canvas by your average art student. If the manufacturer has a reputation for quality cookware, then making it from 316Ti is fine. If they don't have a good reputation, I don't care what material they use. Best of luck.

Regards,

A. Hi Amit. This thread includes some helpful guidance on that subject, in-depth answers from Dan Kay and Toby Padfield, and a general impression that the differences for most applications are probably trivial.

Please try your best to frame your inquiry in terms of what was unclear to you from the previous responses, rather than essentially starting over. If that isn't possible, please at least advise us of the premium that is being asked for one material over the other, so people can comment on that and keep the thread moving forward rather than circling its tail. Thanks!

Regards,

 Hi. Thanks Liz, you're certainly as welcome as anyone else to have your opinion posted here, but how do you know what was actually said (as opposed to what may be printed on the standard sales shpiel)? It seems more likely to me that the demonstrating salesperson will spout whatever will promote the sale, than that the potential customer would utterly misquote (although often the truth is halfway between).

Are there any actual chemical test results for this "leaching"? Several metallurgists have told us that such demonstrations test brand new cookware against previously used cookware, so that what you're really tasting is the fact that boiling water and bicarbonate will leach tiny amounts of your previous meals out of previously used pots -- proving not that one metal leaches more than another, but that pots which have been cooked in and then washed are not as clean as we might think :-)

Per our editorial standards, we deleted your recommendation of a specific brand. But are you a satisfied customer of 316Ti with no vested interest whatsoever, or are you a rep? One reason we don't print brand names, and our editorial standards discourage testimonials, is that company lawyers have frequently made us remove negative reviews but have not once in all our years on line complained about positive reviews -- which guarantees unbalanced & overly glowing reviews of any brand that is mentioned ... savvy readers discredit such testimonials anyway, which consume their time without giving them the balanced education they came to this site for. Thanks for your views, but no testimonials please!

Regards,

A. Hi Adedayo. Theoretically, 316Ti is slightly more corrosion resistant than 304; theoretically, 18/10 stainless is slightly more expensive and better than 18/8. But unfortunately it's nearly impossible for a consumer to judge the quality of such products from sales blather and the "specs" included in it.

If you don't know anyone who has the product you are considering buying, you can try review sites like Amazon and read about the buyers' level of satisfaction; I wouldn't necessarily trust a single review, but a large number of favorable or unfavorable reviews would carry some weight for me. Good luck.

Regards,