paul
Member
Posts: 8
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Steels
Feb 8, 2008 21:01:21 GMT
Post by paul on Feb 8, 2008 21:01:21 GMT
I think I might have asked this before but couldn't find the thread (and let's face it, I have asked a lot of questions!).
Are there any easy ways (or tips or hints) to differentiate different types of steel, especially silver steel vs stainless? I have a fair few bits that have got mixed up and I'd like to be able to organise them.
I have seen some people sniff steel presumably certain types have a distinctive pong? Or maybe they just like doing that.
I suppose there might be a way to detect silver in steel (like putting wet aluminium foil on silver and getting bad egg city)...?
On the same theme what about the various types of Iron? Any help gratefully accepted.
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jackrae
Elder Statesman
Posts: 1,333
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Steels
Feb 8, 2008 21:17:37 GMT
Post by jackrae on Feb 8, 2008 21:17:37 GMT
Sorry to disappoint you but there ain't no silver in them thar hills. It's just a name to describe a particular grade. (But there is silver in silver solder)
"Steel" which is non-magnetic at ambient temperatures is likely to be 316 grade stainless steel. But there again there are probably a thousand alternative recipes which are also non-magnetic
Jack
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Steels
Feb 8, 2008 21:52:19 GMT
Post by chris vine on Feb 8, 2008 21:52:19 GMT
Hi Paul, If you leave it outside and it doesn't rust it is probably stainless. Although it might not be! Also non magnetic could be stainless. A good test is to touch it onto a grinding wheel. mild steel and silver steel give off very different colour and shapes of sparks. Mild steel is more yellow, silver steel (and high carbon tool steels) are much more red. Mild steel tends to do fairly straight lines with little sparks at the ends Silver steel tends to do lines and them star burst sparks, more like a sparkler. There are much better descriptions and drawings in Tubal Cain's Model Engineers Handbook. Also see shopswarf.orcon.net.nz/spark.htmlen.wikipedia.org/wiki/Spark_testing_metalsor google steel spark test. You can also try machining them. Also mild steel, if heated to red heat and quenched in water will not be hard whereas silver steel will be hard and brittle. A file will not touch it. You will find with Mild Steel, especially stuff you are given from works, skips etc. can differ a lot. There is a huge difference in how the free cutting types cut, compared to the ordinary stuff. It matters more for us than for industrial folk because our machines do not have the same sort of power and rigidity. Hope that helps.... Chris.
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hat
Active Member
Posts: 48
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Steels
Feb 9, 2008 8:31:31 GMT
Post by hat on Feb 9, 2008 8:31:31 GMT
Only this week I made a pin drill out of what I thought was silver steel - nicely made, ( to the G Thomas spec) hardened and still soft!! Spark tested it and still couldn't decide, referred to Tubals bible and still could not be sure -other than it was not Silver steel. Chris pointed to the article on "shopswarf" which does seem more definitive. But as a general principle what is the carbon content of "silver steel" Hat
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paul
Member
Posts: 8
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Steels
Feb 9, 2008 8:48:44 GMT
Post by paul on Feb 9, 2008 8:48:44 GMT
Sorry to disappoint you but there ain't no silver in them thar hills Aw, that'll teach me to assume! Chris: most helpful thank you! The magnet and grinding wheel looks like it will have to suffice; I don't fancy heating/machining/filing every last tiny bit! I guess as long as known stainless and known silver is used where necessary the rest can go hang! I'm off to do some grinding...
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Steels
Feb 9, 2008 10:30:49 GMT
Post by alanstepney on Feb 9, 2008 10:30:49 GMT
Peter Stubs Silver steel is: Carbon, 1.1%-1.2%: Silicon, 0.1%-0.25%: Phosporus, 0.045% max: Manganese, 0.3%-0.4%: Sulphur, 0.045% max: Chromium, 0.4%-0.5%.
As for the spark test, and specifically for silver steel, the only way I find I can check ss is to first grind a piece of known ss, then compare the sparks with the unknown steel. That soon shows if they are the same material.
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abby
Statesman
Posts: 925
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Steels
Feb 9, 2008 12:02:51 GMT
Post by abby on Feb 9, 2008 12:02:51 GMT
Unless you are experienced spark testing of steel is not very reliable, except in the case of HSS which will give a blood red spark - as does cast iron, most carbon steels will give a yellow white spark. As already stated , most stainless steels are non-magnetic , but monel and nimonics are also non-magnetic and look very similar(see recent post re boat propeller shafts). Silver steel has a precision ground finish which , unless your stock is rusty like mine , should be a give-away when comparing with any other bar stock which is cold drawn. If you are like me and throw odd bits in a scrap bin which is then raided for stock a good idea is to colour code one end of the bar when you buy it - or otherwise , like your files , colour code files to be used only for brass and they will last a very long time.
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Noddy
Statesman
Posts: 672
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Steels
Feb 11, 2008 9:54:40 GMT
Post by Noddy on Feb 11, 2008 9:54:40 GMT
As already stated , most stainless steels are non-magnetic , but monel and nimonics are also non-magnetic and look very similar(see recent post re boat propeller shafts). Just to spread some alarm and dispondancy:The few stainless steels which are magnetic include the hardenable martensitic stainless steels. There is also a rusting steel which is none magnetic (austenitic manganese steel), it gets used for things like rock crushers, railway points, bucket teeth and dozer tracks, lovely stuff. I suspect that the spark test is picking up more on some of the other componants such as Manganese and silicon, rather than the carbon content.
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Steels
Feb 11, 2008 21:52:49 GMT
Post by steamjohn248 on Feb 11, 2008 21:52:49 GMT
If you buy Stubbs Silver steel it is stamped as such at the end of the bar, cut bits off from the other end and you'll always know
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