Steel grade

[Benni DregildParticipant @bennidregild28760]

Hi!

I'm totally new in Model Engineering – has just bought a Proxxon lathe PD 230 – and read ”Lathework – a complete course” by Harold Hall.

From the local blacksmith I have got some 25 mm steelbars of grade S235JR. I have tried to turn a piece down to 24 mm. It goes relatively well but produces some very long chips (30 to 40 cm).
Would the process become easier and the result better if I bought some 230M07 steel (from England) which I have not been able to get hold of in Denmark?

[Benni DregildParticipant @bennidregild28760]

[JasonBModerator @jasonb]

I think that is a hot rolled structural steel which would be like our R25 reinforcing rod.

Although the long curls of swarf (chips) are not really an issue this type of steel does not usually produce a very good finished surface. So yes the 230M07 (EN1A) would be a better choice

[jason udallParticipant @jasonudall57142]

Welcome to the "club"

230M07Pb steel or En 1APb might be known more europeanly ( locally) as 11SMnPb30

The leaded versions are known as freecutting and will be a much simpler and pleasureable material to turn.. ( but don't use if part needs to be welded later.).

[john kennedy 1Participant @johnkennedy1]

Posted by jason udall on 07/01/2013 16:33:55:

( but don't use if part needs to be welded later.).

Oh dear,could that be a problem.Planning on welding some in the near future.

John

[Nicholas FarrParticipant @nicholasfarr14254]

Posted by john kennedy 1 on 07/01/2013 18:32:21:

Posted by jason udall on 07/01/2013 16:33:55:

( but don't use if part needs to be welded later.).

Oh dear,could that be a problem.Planning on welding some in the near future.

John

Hi John, welding freecutting steels is not recommended, because in the majority of cases failure will occur in the heat affected zone (HAZ) without suitable and controlled heat treatment after welding.

The heat treatment required is largely dependant on the thickness of section and the nature of the joint, and is normally outside the scope of the home workshop. I would certainly say not to weld anything that is life dependant using freecutting steels.

In my maintenance years, I've seen 4" (100 mm) shalfs snapped like a carrot without any warning when freecutting steel was wrongly used in conveyor belt systems when welded into the pulleys using industrial welding plants and skilled welders. The same jobs using non freecutting steels never failed.

Regards Nick.

[Sub MandrelParticipant @submandrel]

What no-one has said is that if you get the versions that don't have the 'Pb' in the name, then they will be OK to weld, and only slightly less easy to machine.

Note that EN1A (by any name) is not the toughest or strongest steel, though fine for most 'model engineering' applications. It would help if you told us what you are making. If its just to get used to the lathe, use the leaded versions as these are very forgiving, and then using ordinary steels (even much tougher ones) later will come naturally.

Neil

[Benni DregildParticipant @bennidregild28760]

Thanks for the answers so far. My plan is to get to know the lathe by making some of the smaller projekts in Harold Halls book and if that goes well move on to a Elmers # 25. Model engineering seems not to be a wide spread hobby in Denmark, and getting hold of tools and metals is a problem if you want to buy as a private person. On Your advice I I therefore intent to buy some 230M07 from an english e-store. Do You know of any Danes in this forum?

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