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Letter 29294
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++++ Which metal is more durable: 18/10 or 18/8 stainless steel? I am considering purchasing some flatware that is 18/8 stainless, and wonder how strong it will be. Thanks, H Dawson
++++ Previously on another Internet forum: Question |
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Answer
Hello Shelly! Let me start with a few basics, OK? The 18/8 and 18/10
designations are older terms, and refer to the amount of chromium and
nickel alloyed with the iron, to comprise the stainless steel. The
18/8 name has been pretty much replaced, in the States at least, by
several other designations. 301 stainless steel has 16-18% Cr, and
6-8% Ni 302 stainless steel has 17-19% Cr, and 8-10% Ni 304 stainless
steel has 18-20% Cr, and 8-10.5% Ni That may explain your difficulty
in finding information on these alloys. Similarly, 18/10 is usually
referred to as 316 stainless steel, with 16-18% Cr, 10-14% Ni, and
also 2-3% molybdenum, which greatly increases the resistance to
pitting corrosion in seawater. Good stuff, that moly.
Now the mechanical properties these 300 series stainless steels are all the same! In the annealed condition, they are all listed at 75 ksi tensile strength, 30 ksi yield strength. The slight difference in Cr and Ni isn't enough to cause a difference in the strength by themselves. These alloys can be made harder, however, by cold working, i.e. rolling or drawing through a die or extruding through a die or some other such process which will deform the metal, while it is at most a few hundred degrees F. Here, too, the mechanical properties are the same: half-hard stock, for example, has 150 ksi tensile, 110 ksi yield strength, no matter if it is 301, 302, 304, 316, etc.
The difference is in the corrosion resistance (which I assume you're not interested in, since all will be fine for flatware) and in the ductility. A lower alloyed 301 has more ductility when work hardened than the higher alloyed 316. So after you stamp out your quarter hard sheet into forks, you can bend one of the tines more often, or farther, if it is of 301 rather than if it is made of 304 or 316, before it will crack. The weight of the flatware will depend on geometry, since the densities of the stainless steel grades are identical, for practical purposes. Iron, chromium, and nickel all weigh about the same. A splendid source of information on stainless steels is the Nickel Development Institute, at www.nidi.org, which offers a lot of FREE literature they are glad to send. And please don't hesitate to ask here again! (Gosh, I hope I answered your question in all this rambling!) Take care!
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Lee Gearhart |
Very informative answer. Now I'm wondering about 18/0. I've seen a number of flatware sets listed as such. Does the 0 indicate lower quality, less corrosion protection, what not?
Amanda G
- Jetmore, Kansas
Because nickel costs about $17 per pound, flatware which contains none would be less expensive than flatware which contains 8 or 10 percent nickel.
While 18/0 is not necessarily unsatisfactory, it is not as corrosion resistant.
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++++++ Is any grade better for one's health than another? I'm particularly interested in stainless steel cooking ware. Clarissa
D
Now that I understand about 18/8 and 18/10 - what about flatware that doesn't bend? Laurie
B
Hi, Clarissa. Sorry I have no answer except that all of these stainless steels are considered safe, and it seems to me that what your pot is made of is relatively inconsequential to your health compared to what is in the pot :-) Hello, Laurie. That has much more to do with the dimensions (and consequently the weight) than the type of material. In this context the resistance to permanent bending is proportional to the second power of the thickness. As a slight simplification, flatware that is 40 percent thicker will be 40 percent heavier and twice as strong. So flatware, like produce, should be "heavy in the hand".
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+++++++ Is it true that type 304 surgical stainless steel cookware will react on food while 316L will not? They said this kind of stainless steel (316L) is what surgeons use for hip, knee replacement and others. I attended a cookware demonstration where they boiled water on each different cookware (aluminum, copper, stainless steel and 316L stainless steel) and put a teaspoon of baking soda and all the cookware has a yucky taste including the regular stainless steel except for the 316L, no reaction at all, why is that? I've been surfing the internet, couldn't find the answer. Gabriel D
+++++++ I also have the same question. A lot of waterless cookwares are using 304 stainless steel and only SaladMaster is using 316L. Is 316L really a lot better than 304? I have heard that 304 has pores when heat up, but not 316L. Is it true? Elena Au
Gabriel, The demo you saw was no doubt carefully configured to show 316L in the best light. Still, 316L is more corrosion resistant, although probably no "safer", than the other stainless steels mentioned on this page. Elena,
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I have found a number of third-party sources that verify the
superiority of 316 steel, versus lower grades of stainless steel on
the market such as 304 and 18/8.
Here is some very interesting data on 316 steel, according to the
Sandmeyer Steel Company:
http://www.sandmeyersteel.com/316-316L.html
Here is a quote from this page:
316 steel is used in the "manufacture and handling of certain food
and pharmaceutical products where the molybdenum-containing stainless
steels are often required in order to minimize metallic
contamination."
Here is a website where I found that Pharmaceutical companies use 316
steel for purposes of high purity in their products:
http://www.arcmachines.com/appPages/weldspec02.html
Here is a quote from this page:
"The Baseline series of PHARMACEUTICAL ENGINEERING GUIDES was
developed by ISPE in cooperation with the FDA to establish a baseline
approach to new and renovated facility design, construction
commissioning and qualification. . . . discusses material selection
for piping systems and recommends type 316L as the preferred steel
for a High Purity Water generation and distribution system. "
I also have data from multiple Allegheny Ludlum metallurgical studies
that demonstrates the differences between 304 steel and 316 steel.
Joseph Matthew Gleason
- Anna, Texas
November 16, 2008
OK, back to the original question – what grade of stainless steel
should I use for cooking utensils?
I work for a company that fabricates carbon steel and stainless steel
piping systems for food processing plants, water treatment plants and
industrial users. My job is to help with selecting the best (most
cost-effective) materials for our customer's specific
applications.
18-8 stainless steel – now most often referred to as 304 or UNS
S30400. – Good, general purpose stainless steel. Used for some
drinking water plants, petrochemical plants, lots of structural uses.
If you want to make transit bus handrails, use 304. It's resistant to
most chemicals, and won't pit or corrode from people's sweaty hands.
Good for cooking utensils, but not as goods as 316.
18-10 stainless steel - now most often referred to as 302 or UNS
S30200. About the same for food use as 18-8. Lots of good,
inexpensive cookware is made with this alloy.
18-10MO - now most often referred to as 316 or UNS S31600. This is
the alloy of choice for food processing equipment and applications
requiring excellent corrosion resistance to most chemicals. 316 has
18% chrome, 10% nickel and 3% molybdenum. The molybdenum has a major
effect on resisting acidic and chloride corrosion. Lots of foods are
acidic – tomato sauce is one that will pit 304 but not 316. Just
about everything you cook has salt in it, and salt (especially sea
salt) has high chloride levels.
However, most if this is irrelevant. Unless you're running a meat
packing plant next to the ocean (and they all use 316), any of these
grades of stainless will work just fine.
How to destroy stainless steel cookware:
> Use with plain steel items. In our plant, we carefully segregate
stainless steel from plain carbon steel. All of our shelves are
coated with plastic so the stainless steel never touches carbon
steel. Having both types of steel in contact may cause the stainless
steel to develop surface rust. Using stainless steel spatulas on cast
iron frypans may cause rust marks to develop on the spatula. Don't
use plain steel wool to clean your stainless steel pots – use a
ScotchBrite pad or stainless steel wool.
> Let them soak for hours. Leaving your spaghetti sauce pot in the
sink full of tomato-ey water is the perfect way to start pitting.
Stagnant acidic water is the worst thing you can do. When we design
tanks for food processing plants, we take special care to make sure
the tanks can completely drain and there are no crevices to collect
stagnant water.
Bottom line, any good-quality 18-8, 18-10, 302, 304 or 316 stainless
cooking utensils will be head and shoulders beyond most of the other
available materials. Teflon-coated pots chip and flake, glass breaks
and discolours, copper tarnishes and often contains lead, strong
detergents dissolve aluminum.
As for the SaladMaster demo, it's a trick. When the nice SaladMaster
salespeople boil water in your pots and pans, you're comparing the
results against the brand new, never-been-used SaladMaster pots they
brought with and unwrapped in front of you. Your pots and pans have
millions of microscopic surface cracks that may trap equally
microscopic food particles. That's what you taste – the boiling water
and baking soda leaches out some of the food particles, causing the
yucky taste. The brand new SaladMaster pots have never been used, so
no food in THEIR microscopic cracks, so no taste.
Sheldon Jaffe
- Langley, B.C., Canada
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+++++++ My son struggles with metal toxins, and I am at a loss as to which brand of flatware would be the least toxin for him. He is now in a treatment program to detoxify his body of metal toxins, and I don't want to put toxins back into his system. I have read this and that about 316 steel etc, but I am still unsure as to what flatware to get. Please help by sharing a brand(s)of non-toxin quality flatware. Thanks so much! Deborah Jan
Evgenikos
In answer To: Russ
Goodrich Ed. note: If unable to use commercial silver polish, then see letter 4785 for removing tarnish from silver with baking soda.
+++++++ re: Linda
Fischer
I don't think that that is accurate, Linda. The usual alloying material in sterling silver is copper, and silverplate or silver would probably be the least allergenic.
May 20, 2008 In answer To: Keith
Savage |
I have a new set of flatware that is marked "stainless china". Can you tell me about this flatware and possibly why it tarnishes every time I put it in the dishwasher?? Now my other flatware and utensils are tarnishing too. I've had the dishwasher checked and cleaned it out with vinegar washes several times. Please help!
Linda Knepp
housewife - State College, Pennsylvania
The "Stainless China" flatware is tarnishing each time you put it
in the dishwasher because it was MADE in China (it's not "china" in
the ceramic-plate sense). The stainless indication means that it has
a higher level of chromium than standard steel, but most likely a low
(if any) nickel content. You want to buy something that says 18/10 or
18/8 right on the handle.
Eric
Eric Larson
- Simi Valley, California
January 1, 2008
As I read through all the answers I got more confused! Which is the better flatware? Is more nickel better? heavier? pricier? I need high quality, pit and corrosion resistant, heavy flatware in my hand. What is the very best? Which should I buy if price is not a consideration only quality,durability and beautiful finish are the criteria? Help! I hate cheap flatware so much I can't eat with it, it literally hurts my hand!
Gail Robinson
buyer - Willimantic, Connecticut
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Hi, Gail. Please read the replies slowly and ask for clarification on points you didn't understand. Starting over doesn't eliminate the confusion you complain of -- it makes it worse :-) As noted, all stainless is about the same density (weight) and strength. More nickel is better, more corrosion resistant, and more expensive. 316 (sometimes called 18/10) stainless steel is best, and 304 (sometimes called18/8) is almost as good. But I don't think you can really select flatware on this basis, because there is more to the process of manufacturing good stainless steel than just the alloy composition. I think you can go only by the reputation of the maker and their guarantees. Although I am a proponent of "Buy American", I believe that no stainless flatware is made in the USA. It's almost all made in China today, and I have zero confidence in it or the companies selling it. If anybody knows of American-made place service, please pipe in. I have no personal experience with Japanese flatware, but at least Japanese companies don't seem to practice "meatball whoring" like so many American companies do today (letting any schlock outfit put their company's meatball/logo on a product in exchange for a licensing fee). Based on what I can see, their lifetime guarantee, and customer reviews, my personal guess as to the best flatware you can buy today is Yamazaki. If anyone has personal experience with it, please chime in; meanwhile we've linked to reviews on Amazon where all three customers rated it "5-star". Good luck.
May 5, 2008 This is very helpful and informative reading. Thanks everyone. I am replacing my Reed & Barton 18/10 flatware after 11 years due to staining and pitting. Nothing last forever. And it look as though the standard is still 18/10 (316). Considering Oneida or Yamazaki... Maureen Moylan
January 31, 2009 I just bought a set of Yamazaki and all I can say is that I think it is very important to have flatware that feels good in the hand, has a good weight and looks beautiful...and this brand delivers on all counts. It is marked 18/8 and "made in China", and while I don't know how it will wear, my initial impression is that it is well designed, well made, and that the company pays attention to quality. No small thing these days! Rhonda Shaw |
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+++++++ Hi. I just came across a 21/0 stainless steel flatware which I am considering purchasing. According to what I've learned here, this signifies 21 percent chromium and 0 percent nickel. Is this better or worse, lighter or heavier than 18/10 stainless steel flatware? Thanks! Beatrice
Finkelstein
January 31, 2008 I am also curious about the 21/0 stainless steel flatware I see advertised. Is anyone able to offer an explanation on the durability or quality of 21/0? Jacque Perry
March 8, 2008 If you read between the lines, the key factor in the ratings is the amount of Nickel in the item. The Nickel is the metal that reduces the rust and pitting of the base metal, being Stainless Steel. Stainless Steel is a combined metal of steel, nickel, chromium, titanium and others. The SS rating also indicates a hardness, as 21 will be harder and stronger than 14, though less flexible, meaning it should last longer in use. The second number in the equation for flatware as in 18/10, being the 10, indicates the percentage of nickel being used. Most common ratings as in 18/8 - 18/10 are the basic and accepted range for flatware. A 21/0 therefore is a strong SS with minimal nickel content. Most of these utensils have been polished. With minimum nickel content, the polish will not hold up very long and will lend itself to staining long term. Dell Wood |
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i would like to know if lead is ever used in making flatware. I am concerned because of China's deceptive use of lead in products.
Barbara McBroom
- Hillside, Illinois
Hi, Barbara. I can't see any reason a manufacturer would put lead into a stainless steel product. However, if you were talking silver plated flatware, there probably are some machinability advantages to making it from leaded brass.
That doesn't mean I personally believe there will be lead in a piece of silverplate, but based on the news, I'm certainly not making any promise on behalf of a Chinese manufacturer.
Regards,
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 Ted Mooney finishing.com Brick, New Jersey |
Can you tell me if there is any aluminum in 18/8 stainless?
Thank you,
bjh
Barbara Hammar
- Corvallis, Oregon
Hi, Barbara. No, there is no aluminum in 18/8 stainless.
Regards,
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Ted Mooney finishing.com Brick, New Jersey |
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September 10, 2008 I read all the questions and answers and they are very informative. However, I did not see anything about stainless steel cookware that's 18/30 grade. What would this mean? Maria
Chua
Thanks for the interesting discussion. I want to buy a steam cleaner, and have been looking at different models that have stainless steel boilers. Most of the boilers are 18/10 steel, but one somewhat less expensive one is made of 12/10 steel. If this means the amount of chromium is lower in the steel, will the boiler be less durable over time? Thanks, Janine
Polk
Hi, Janine. I've never heard of type 1210 stainless steel, and a quick check of google didn't reveal any such thing either. Are you sure the "1210" isn't simply a model number as opposed to a type of stainless steel? Regards,
No, the machine is always listed as having a 12/10 stainless boiler. It is the Unilux 3000--here are a couple links for it. In the second link check the comparison chart a little ways down the page. www.allbrands.com/products/abp13897.html?ovchn=SPRI&ovcpn=Froogle&ovcrn=Froogle&ovtac=CMP# www.smart-cleaning-solutions.com/site/1426224/page/825600 Actually, in the bottom chart (steam cleaners with extractors) I see there are several models with 12/10 boilers also. Is this just a mistake, and they actually all have 18/10 stainless boilers? Janine Polk
Hi, Janine. Remember that catalogs are written not by metallurgists but by sales & marketing people, and that errors creep into everything. But in this particular case it says the boilers are made of type 304 stainless steel (which is an 18/8 stainless steel); I believe they are trying to say that the thickness of the steel is 12 and 10 gauge (maybe 12 gauge cylindrical shell and 10 gauge top and bottom plate/bell). One reason I believe this is that the heavier gauges seem to be specified on the higher pressure models. Regards,
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I am about to buy a very very large quantity of stainless steel
tableware for a huge dining facility I will be moving my current
facility to. We serve meals to over a thousand people 3 times a day
and the tableware gets a lot of use. What I have been using is 18/10,
and we have specifically gotten this because it is very durable. I am
trying to save money and so I am considering buying 18/8 instead. I
guess I wanted some opinion on whether I should save the money buying
a lower grade, or save money by having a more durable 18/10 which
lasts longer. But my question is, is it really worth the difference,
and based on your experience with the metals, what do you think would
work better for me? Also, is 18/8 magnetic like 18/10 is.
Thank you!
Rosemary Johnson
buyer - Tampa, Florida
Hi, Rosemary. 18/8 is not magnetic and neither is 18/10. 18/10 is better and more expensive but I think it's unlikely that a quality brand of 18/8 would be unsatisfactory.
Regards,
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Ted Mooney finishing.com Brick, New Jersey |
I have an 18/8 stainless steel sports bottle that is magnetic as well. If 18/8 is not supposed to be magnetic, what would cause it to be so?
Patti Douglas
buyer - Portland, Oregon
Hi, Patti. Cold working during manufacture can leave 18/8 with a very slight magnetic attraction. But if it's significantly magnetic, like regular steel is, I'd say it is not 18/8.
Regards,
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Ted Mooney finishing.com Brick, New Jersey |
HI..good info here. I am looking at purchasing a new set of pots
and pans..the description says 18/10 lids
ok.what are the pots made from, or are they saying lids and not
addressing pots, because of the copper bottoms?
at a loss...
J FRED MUGGS
- Meadville, Mississippi
Hi, J Fred Muggs. Your parents certainly had a very weird sense of humor, trying to make a monkey out of you. My sympathies!
If the manufacturer doesn't claim 18/10 I think it would be a leap of faith to expect it.
Regards,
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Ted Mooney finishing.com Brick, New Jersey |
Great to see all of this chat on Stainless. I'd like to add one factor - the higher nickel content allow a much brighter and whiter shine. It's apparent in cookware as well. If you use 18/0 which I think is also 201 (not sure) in flatware and cookware it dulls quickly over time. It's still food safe just not as nice to look at after a few uses.
Bradley Smith
- Sacramento, California
The debate between 304 and 316 on leaching metal toxins is
fascinating. I understand they are both inert.
I am making Kombucha tea, which is a highly acidic fermented tea.
Would 304 or 316 be more suited, for continuous repeated home use.
Better than glass even? The culture would ferment for up to 30 days
in the vessel in black tea and sugar. Any help would be great don't
want to make family sick.
chad york
- puyallup, Washington
April 23, 2009
Hi, Chad. Type 304 and 316 stainless are quite similar, but type 316 is more corrosion resistant. I think that is all that could be said short of retaining a laboratory to ferment the mixture for 30 days and then testing for dissolved metals.
But glass is completely inert to food products.
Regards,
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Ted Mooney finishing.com Brick, New Jersey |
April 4, 2009
We need to replace a 28-yr old kitchen sink. Which would be more
durable and best:
"20 gauge, Type 304 Series stainless steel w/satin finish 18/10
chrome-nickel content"
or
"18 gauge, 18/10 stainless steel"
We've always though the lower gauge was better, but the Type 304 is a
new wrinkle since we bought last.
Thank you.
Bobbie Cavano
consumer/buyer - Rome, New York
Hi, Bobbie. 18 gauge is heavier than 20 gauge. Type 304 and 18/10 are essentially the same thing. The wording "type 304" is just a little more exacting about the composition than the more generic 18 percent chrome 10 percent nickel.
Regards,
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Ted Mooney finishing.com Brick, New Jersey |
Thank you for taking the time to respond.
Bobbie Cavano
consumer/buyer - Rome, New York sp
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I was recently in India and a lot of the factories are
using 14/1 and 14/04 stainless instead of 18/10. The price
is reduced and the factories are saying that products
manufactured from 14/1 and 14/04 pass all tests for
corrosion and rust. Diane Stevens
June 16, 2009 Hi, Andrea Thien
June 18, 2009 Hi, Andrea. I didn't comment because I've never heard of it. Sorry. Does anyone know the composition or anything else about it beyond that they call it "14/1" ? Thanks. Regards,
June 15, 2009 I'm a sales man of a stainless steel tableware factory from mainland china, so great to learn so much from those interesting discussions. However I still have a question here: in our country,we usually apply the 420 type of SS to make knife items of a tableware set. As far as I know, it's much harder but less corrosion resistance, is that due to the less nickel added to the alloy? what's more,I haven't seen any discussions about this kind of SS, while it's widely used in our country in such field, how do you name it in your country. thanks. Tobby.Xiao
July 2, 2009 I did some sleuthing and found out the following. The
opinions stated below are from a kitchenware manufacturer.
Does anyone know more about patta and if J4 is better then
J7 or anything on the coil vs patta quality? Andrea Thien
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