which stainless steel?

Chris Burton · Dec 31, 2008

I want to make a pair of corn cob holders for a friend. Need some ss for the spikes. What kind of stainless steel rod is best to use? I know nothing about the different numbers that are used to describe these things.

many thanks,
Chris

Ries · Dec 31, 2008

304 will work fine.
probably 90% of the scrap stainless you run across will be 304- its the cheapest, and most common.
It sometimes rusts a tiny bit in the dishwasher, especially if you forge it to get your points.
Hand washing is better.
It wont hold an edge, like a good knife will- for that, they use 400 series stuff, which rusts a lot more, but can hold a fine edge.
But for corn holders, you dont need surgical edges anyway.

Chris Burton · Dec 31, 2008

Great. Thanks for the info.

Blue Steel · Jan 3, 2009

Most of the 300 series will be just fine. As a point of interest 316 is the same as 18-10 PH which is the one cutlery makers use for their stuff. I think 304 is the same as 17-4PH which is used for professional chef's knives. PH stands for Precipitation Hardening. If you want a really sharp edge then your heat treatment is important.

I think for what you are using something in the 300's will be fine, it won't matter too much which one. SS in the 400 series has much less Chrome and Nickel so rusts more.

Stephen

Bobw · Jan 3, 2009

Blue Steel said:
As a point of interest 316 is the same as 18-10 PH which is the one cutlery makers use for their stuff. I think 304 is the same as 17-4PH which is used for professional chef's knives. PH stands for Precipitation Hardening. If you want a really sharp edge then your heat treatment is important.

I see a lot of bad info right here.

17-4 is NOT 304 (I think its actually 630, though I may be wrong), two totally different animals, and 300 series stainless steels are not heat treatable, they can only be hardened through cold working, they can be annealed back to gooey after cold working if I remember correctly.

I would also question the use of 316 in cutlery, 316 is generally pretty gooey stuff and not heat treatable, which would make for a really crappy knife. It would make a pretty knife, just not a good one, generally the blades I've seen are 440C.

Back to the original question, I've seen some 304 wire that was hard as nails, in the 46C range, that could work quite well, except I couldn't get the stuff straight, it was like a spring.

Actually, some 308 filler rod would probably work really well, dirt cheap, straight, and you can get it in small quantities locally.

On edit, Blue Steel, noticed you're from down under, I'm pretty sure you guys aren't using all the same designations that we are over here, we're about 40 years behind the times, the kings foot still rules.

gwilson · Jan 3, 2009

440 is only stainless after hardening.

Blue Steel · Jan 4, 2009

MMMMMMM

Precipitation Hardening Stainless Steels (% Max.)
Type Trade Design C P S Si Mn Cr Ni Mo Other
Martensitic
630 17-4PH 0.04 0.020 0.010 0.60 0.25 16.0 4.00 * cu 3.2, cb+Ta 0.25

OK doing a quick browse I found this, so 17-4PH seems to be 630. Not sure if that is what they mean by type but others might know more.

Classification of Stainless Steels

Based on alloy contents, internal structure, magnetic or non magnetic properties, and other
qualities, stainless steels can be broadly classified into under noted five categories.
1. Martensitic Stainless Steels
Martensitic Stainless steel contain 11 to 18 % chromium along with carbon in specific percentage, making it hardenable by air cooling. These stainless steels are extensively used for cutlery, knives surgical instruments, industrial blades, chemical plant equipments, aerospace applications and other industrial components. In addition to chromium and carbon elements like nickel, molybdenum, vanadium, tungsten etc. are also added in some special purpose grades.
2. Ferritic Stainless Steels
These stainless steels contain chromium in the range of 11 to 30% with no or very little nickel, are ferromagnetic in nature and generally not hardenable by heat treatment, provide good corrosion resistance and good formability at low cost, and are extensively used for many automotive components. Inferior weldability of these steel can be improved by alloying with titanium or columbium A 15430 is the general purpose stainless steel of this group.
3. Austenitic Stainless Steel
These steels contain 16 to 30% chromium 6 to 20 % nickel and low carbon content, has excellent corrosion resistance, high ductility and toughness. Work hardening during cold working helps to get desired mechanical properties. These can not be hardened by heat treatment. In AISI 200 series steels, nickel is partially substituted by manganese and nitrogen is also added which helps in improvement of corrosion resistance, strength and stabilisation of austenitic structure. In some grades, copper is also added to improve cold forming and corrosion resisting properties. Austenitic grades are most widely used stainless steels. 200 series grades are having higher strength than 300 series stainless steel.
4. Precipitation Hardening Stainless Steels
These steels contain titanium, copper, niobium, aluminum, tantalum, phosphorous which
precipitates during ageing or heat treatment and improve the mechanical properties of the alloy. Precipitation hardening steels are of three types viz, austenitic, semi austenitic and martensitic are corrosion and oxidation resistant and retain its strength at elevated temperature. These are mostly used in aerospace applications.

5. Duplex Stainless Steels
In these steels structure is controlled in order to give equal ferrite and austenite to develop
excellent corrosion resistance property to with stand chloride steels corrosion cracking. These steels exhibit higher yield strength than the austenitic grades and better resistance to chloride corrosion, of these properties makes it suitable for fabrication of various industrial equipments for typical corrosive environments, where austenitic or ferritic grades are generally found unsuitable.

So read into all of that what you want. I have machined a lot of 316 and it can work harden pretty badly. As to heat treating you supposedly can't and who would bother trying anyway? You certainly can harden other Stainless Steels.

I have pretty much repeated BobW here.

Checking further http://www.bssa.org.uk/topics.php?article=91 The British Stainless Steel Association lists 18/10 as 304.

Cutlery stainless steel grades '18/8', '18/10' and '18/0'

Compositions of '18/8', '18/10' and 18/0'

These figures relate to the chromium and nickel contents of the steel, respectively.

'18/8' is probably the most commonly used stainless steel and contains 18% chromium and 8% nickel.
This steel is also known as '304' (in the American AISI grade designation system) or 1.4301 in the European BS EN 10088 standard.
It is an 'austenitic' type of stainless steel and so is not (or only very weakly) attracted by a magnet.

'18/10' is a designation used on some cutlery and holloware as an alternative to '18/8'. This designation is claimed to indicate a better quality steel than '18/8', and is essentially the same as the '304 (1.4301) grade .

'18/0' is a 'ferritic' stainless steel type, which is attracted by a magnet (like pure iron). This steel is known as '430' in the AISI system or 1.4016 in the European standard.
It is used where corrosion resistance is not too demanding as an alternative to the '18/8' 304 type. The chromium content is around 18% but there is no nickel addition.

Stephen

Bobw · Jan 4, 2009

Blue Steel said:
MMMMMMM

I have machined a lot of 316 and it can work harden pretty badly. As to heat treating you supposedly can't and who would bother trying anyway? You certainly can harden other Stainless Steels.

Stainless's are wierd, I just yanked out a materials and engineering book, it was pretty crappy(1 page on stainless), but some of what it said is that small amounts of certain trace elements are what actually determine how the material will react, along with massive amounts of chromium, manganese and nitrogen(which I don't think anything we are talking about falls into). Something to do with boundaries to grain structures.

I have a better materials book at home(I think) that can hopefully shed more light on it for me, since now I'm curious. It is weird how you can work harden 300 series, but can't heat treat it, I'm sure that if you get down onto the microscopic level it really is cold working the material, shearing(cutting) can't happen without some type of rupture of the material somewhere, and rubbing is definitely working it.

On the 400 series not being stainless until heat treated, from what I just read, thats pretty much correct. The chromium in annealed 400 series is actually outside the grain structure of the base metal, and heat treating precipitates the chromium into the other metals, I guess its kind of like your marshmallows melting into your Lucky Charms.

Interesting stuff. BTW, no expert here, I know how to cut it and a lot of its macroscopic properties, but this molecular stuff, well... I didn't pay much attention during materials classes, it didn't interest me at that point, nothing concrete to tie it to, I didn't even know what 17-4 was.

10KPete · Jan 4, 2009

I'm a new member but I think I can add some value to this thread. I've done a lot of work in the last 50 years with SSTL and a lot of stainless stuff for boats in the last 10 years.

Here are some links I've found to be quite good on SSTL:

http://www.machinist-materials.com/stainless_table.htm

http://www.machinist-materials.com/stainless_table_two.htm

And for the very academic among you:

http://www.msm.cam.ac.uk/phase-trans/2005/Stainless_steels/stainless.html

Alloy 316 is the one we prefer to use for parts that will be used in a salt water environment as the added moly imparts the required corrosion resistance needed for salt water exposure.

Hope this helps,
Pete

Blue Steel · Jan 4, 2009

Welcome to the list Pete. Top bunch of blokes by and large to hang around with. Looks like you have some expertise that many here will appreciate a lot too

Stephen

10KPete · Jan 4, 2009

Thanks Stephen! I try to give more than I receive but that looks like it's going to be tough to do with this bunch of folks!

Pete

Blue Steel · Jan 4, 2009

*L* you are talking about some of the self proclaimed experts here? NO names mentioned of course.

Guys who are real standouts in any place, RJ Newbould the man who is the only one in the history of the world to have a patent on a basic mechanical device, Psychomill who makes machine tools carve steel faster than most can melt butter, Kennametal is pretty hot on carbide inserts (guess what he does for a living?) Norman Atkinson is one of the more entertaining writers on the web.

Like most I know enough to know I know something but a long way short of everything. The single detail that someone makes known can really bring things into focus for those of us missing out on that detail.

Stephen

USMCPOP · Jan 4, 2009

Can you cut the tines off of a fork and use them?

Another source are those stainless skewers. Should be well less than $1. for a 8"-12" one. Saw some at a kitchen supply site, $14 for 4 dozen of the 8" size.

10KPete · Jan 4, 2009

Blue Steel said:
The single detail that someone makes known can really bring things into focus for those of us missing out on that detail.

Stephen

And that's exactly why I'm here. One of youse guys will be able to fill in that detail from time to time and just maybe I could do the same.

But back to the original question, I would think that just about any SSTL would work fine. I liked the suggestion for using some TIG rod.

Pete

lazarus · Jan 4, 2009

10-4 on the tig rod. You know what's gonna happen when you make them, his wife will tell her friends, you'll have to make a milliom more. At $8.00 a pound, you'll be able to make all of them for under 10 bucks.

Marty Feldman · Jan 5, 2009

303 is reasonably priced and machines quite nicely, at the expense of a very modest loss of corrosion resistance.

tdmidget · Jan 6, 2009

Stainless steel corn cob holders? What next? rolls of paper on the wall? What is this world coming to?

Search

Largest Manufacturing Technology Community on the Web

Search

which stainless steel?

Chris Burton

Plastic

Ries

Diamond

Chris Burton

Plastic

Blue Steel

Stainless

Bobw

Diamond

gwilson

Diamond

Blue Steel

Stainless

Bobw

Diamond

10KPete

Hot Rolled

Blue Steel

Stainless

10KPete

Hot Rolled

Blue Steel

Stainless

USMCPOP

Titanium

10KPete

Hot Rolled

lazarus

Hot Rolled

Marty Feldman

Titanium

tdmidget

Diamond

Similar threads