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Material spec. SCM 20??

Material spec. SCM 20??

Material spec. SCM 20??

We are quoting several parts that the material is designated SCM 20. This is a Japanese part.
Any idea of what the material is and where to get a copy of the spec? I have googled this and come up empty!!
Currently trying to get this without going back to the potential customer as these parts are made in Japan, but the potential customer is attempting to source this in the States.

RE: Material spec. SCM 20??

Take a look here

Double check the stated specification, there is an SCM, the SCM appears to be a designation for low alloy steel. There is also S-CM which is cold rolled special steel sheet.

RE: Material spec. SCM 20??

Thanks for the link, I would agree that the SCM and SNCM would be Alloy steels for machine structural use. These parts are transmission parts so that makes sense. Still did not see a SCM20 designation, there was a SCM420 but that had Cr & Mo in it.
The search continues, We have a list of items to ask the customer I will have to put this on that list at this time.

RE: Material spec. SCM 20??

I checked my 2007 Stahlschlüssel, and found only SCM 21 and 22 with no 20. It could be a steel that was withdrawn as a specification before 2007.

RE: Material spec. SCM 20??

These are defined hardenability structural steels in Japan and Korea.
This is the old designation, the new ones have three numbers and relate to min strength (such as SCM 450)
You need to ask what strength they are requiring.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

RE: Material spec. SCM 20??

Any exemplar of the Japanese made parts to compare with?
I would do my best to find out the elemental composition if at all possible, and this might be done non-destructively with a PMI gun (except for carbon steels, these typically will not be able to distinguish).


There is clearly no Japanese designation of SCM20, so MariolaV is spot on in assessing this to be a Cr-Mo- designation alright, with carbon in the 20% range.

RE: Material spec. SCM 20??

Thanks Cavbilly but the carbon content range must say 0.20% not 20%.

RE: Material spec. SCM 20??

You do not have to apologize to me, especially when pointing out such a glaring misquote on my part. I knew better than that!
I am the one that is sorry. Thanks for bringing it to my attention, asleep at the wheel once again.

RE: Material spec. SCM 20??

Thanks for all the info on this guy's this at least points me in the right direction.
Have another print that has SCY15. So this is Steel, Carbon=.15 & ?
This gets carburized to a depth of .5min after grinding, case hardness is 720-850HV probably a very old Japanese spec also.

RE: Material spec. SCM 20??

Olds468 could you post a picture of that print where say: SCY15 ?

RE: Material spec. SCM 20??

It’s SCr15 = Cr steel whit C~0.15% and Cr~1% mainly (see Cr-Steel in attached image)

RE: Material spec. SCM 20??

Thanks MarriolaV this will help

RE: Material spec. SCM 20??

You’re welcome olds468

RE: Material spec. SCM 20??

This material would be like a SCr415 ?? if there was one on the chart.
Thanks again

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