Identifying Steel types.

[Neil BryanParticipant @neilbryan25499]

Hello Forum,

I posted this question on mycncuk.com and it was suggested I ask it here.

I purchased a length of 'free cutting mild steel' a while ago. I turned various parts using it and was very impressed by the quality of the surface finish. Every other length of 'free cutting mild steel' I have used since has been poor in comparison. I took a sample back to the supplier and they had no knowledge of what it was they sold me. They claimed that all their stock was the same material, but my results showed that this was not the case.


I did some googling on various forums to try and understand what kind of finish to expect from different grades of steel and decided that what I must have was EN1A. I ordered a length and tried some test cuts with the same insert/feed rate/cutting speed/cutting fluid and the results were no where near as good so decided it was not EN1A.



Rest of question will follow.



Neil.

[Neil BryanParticipant @neilbryan25499]

How to identify steel from its properties.

[JasonBModerator @jasonb]

Its possible you had EN1A Leaded which contains a small percentage of lead which generally turns better than plain EN1A.

The modern code for this is 230M07Pb where Pb indicates the lead content

 

J

Edited By JasonB on 10/12/2013 11:52:41

[John McNamaraParticipant @johnmcnamara74883]

Hi Neil

If you plan to arc weld leaded steel you need to consider the pros and cons. It may be best avoided for high strength welds.

**LINK**

Regards
John

[MICHAEL WILLIAMSParticipant @michaelwilliams41215]

Not directly an answer to your question but perhaps something of interest :

Hand held non contact analytic spectrometers are now available which will give a full analysis of a specimen of any common metal alloy . Bit expensive to buy but there are lots of them about now in industry , research labs and academic departments . If anyone ever has a real mystery metal to identify I suggest you ask around and try to get a few minutes use of one of these brilliant pieces of equipment .

MikeW

[RobboParticipant @robbo]

An old fashioned method of determining ferrous metal types was the "spark test". Ideally you already have a sample of known types, and you compare the spark they make when presented to the grinding wheel (density,length, shape of spark) with that made by the unknown specimen.

Could still be useful when checking if one piece of material is the same as another.

Phil

Edited By Robbo on 11/12/2013 21:57:52

[NobbyParticipant @nobby]

Good thinking Phil
Silver Steel the sparks are like a sparkler
Nobby

[davebParticipant @daveb17630]

I bought a rotary table kit from Mr J M Ward a few years ago. There was a piece of round steel bar for making the handwheel. It turned like butter, beautiful finish off the tool. I always meant to ask him what it was.

[SaxalbyParticipant @saxalby]

Re, Mike W's post.

I was given (scrounged) some bar ends of various brasses, some cut well others really quite hard to turn. To cut the story short took a few samples to the local scrap merchant and for the price of a pint, he scanned them all with his handheld spectrometer and gave me a printout of each bars alloy mix.

Barry

[jason udallParticipant @jasonudall57142]

I might suggest.
If welding/soldering are not required then we are left with machinability , corrosion resistance and hardenabilty…
If the latter two don’t feature then the file test is usually suffient. .if it skates and wont cut..hard
If it cuts well then .. free cutting. btw never been able to make the spark test work for m.e

[NobbyParticipant @nobby]

Hi

Stock bars of steel are painted on the end . ie Red for MS blue for free cutting etc for aircraft work materials are in a bonded store and marked , & have to be signed for .
Nobby

[jason udallParticipant @jasonudall57142]

Nobby…yes. worked that way for years.. great until different suppliers use different colour codes. Or when say magenta/white is the code and one end is magenta and the other white so when bar is cut to max length for bar feed, you have white , magenta, and un marked bar. Not difficult to deal with but it leads to much bar that is no longer traceable and thus scrap..
Good for any hobbist ( ) Apart from identifying and that some stock is nasty to turn…but free is free..just don’t let it come back on site.. …
Once had to make some parts out of “fine” silver..sure as hell didn’t mix that up.

[Bill DawesParticipant @billdawes]

When I was an apprentice some 50 plus years ago one of the old boys there used to pick up a bar of steel, sniff it and pronounce EN32 or EN8 etc.

I believed him at the time.

Bill D.

[jason udallParticipant @jasonudall57142]

Sure beats a xray gun…

[AJSParticipant @ajs]

Parker Steel Catalogue gives the following colour identifier markings for steel.

EN3B/EN32 080A15 Blue

EN1A F/C 230M07 Green

EN1A Leaded 230M07Pb Magenta

EN8DM 212A42 Orange

EN8 080M40 Yellow

EN16T 605M36T White

EN24T 817M40T Brown

[NobbyParticipant @nobby]

Hi AJS
Great list . in mould/toolmaking we used various steel KE 672 and before that K9
You dont make Motor Cycles ?
Nobby

[Speedy Builder5Participant @speedybuilder5]

Back in the distant past I remembered polishing the ends of different samples of steel and then degreasing them and etching them with a weak acid. Once done, you could see the grain structure, martinsite, pearlite,lead etc. Can't remember much more, but I am sure the web would tell you.

BobH

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