stainless/silver steel

[firebird]

Hi

You know when you have your 12 lengths of silver steel and stainless steel on the bench, sorting out what you have, and then they accidentally get moved and mixed up, whats the best way of telling which is stainless and which is silver steel? Don't ask how it happenned.

Cheers

 

[DICKEYBIRD]

Wouldn't the sparks be very different between the 2 steels if touched to a grinding wheel? Seems to me it would.

 

[SandyC]

;D

Hi Guys,

Good question...... however, since by far the majority of Stainless steel, used for model engineering purposes, is of the Austenitic type (300 series) then sorting them from silversteel can very easily be done using a simple MAGNET.

Austenitic stainless steel is NON-MAGNETIC, whereas... silver steel is quite the opposite.

Ferritic and Martensitic stainless steel (400series- 500series and some of the 600 series), on the other hand, ARE MAGNETIC, but these would seldom be used for model work.

Hope this helps.

Regards.

SandyC

 

[firebird]

Hi Sandy

Yeah the magnet works a treat. Good tip, thanks

Cheers

 

[Oldmechthings]

Spark testing is a very common method of testing steels, and is used by professionals all the time as a general identification. It is not a substitute for a chemical analysis however. Find a book on metallurgy, and it will probably have a chart showing pictures of spark streams of different metals. Another way is to compare the stream with something that you already know what it is.
I occasionally pick up metal from a freight salvage place in Salt Lake City because the price is very reasonable. Most of the time I cannot tell what the material is until I get it home and spark test it. Then I know if it is plain old cold rolled, stainless, oil, or water hardening tool steel. After testing I mark it with a felt tip pen and put it in storage to be used as needed. A few days ago I posted a topic on heat treating and showed some special cutters that I had made and used. Those cutters were made out of steel from the above mentioned source. I hope this clarifies rather than confuses.
Birk

 

[Powder keg]

I've seen better pictures but you can get an idea of what Birk is talking about Here

Wes

 

[mklotz]

I encouraged members of our club to contribute small pieces of any metal they had with guaranteed provenance to a collection which is available to any member for use in comparative spark testing. If you encounter a lot of mystery metal, you might want to think about doing the same thing.

Most of the textbook spark testing pictures I've seen have been black and white which makes using them rather difficult. We need some kind soul to do a video of spark testing exemplars.

 

[Lew Hartswick]

I could provide a still or two of Titanium. Boy was that an intresting experience.
A movie would be nice but it would be a little dificult to take to the shop and
compare with what is happening at the grinder.
...lew...