EN51??

Nov 02, 2007 11 Replies

I need to make a few 2T semi-diesel hot tubes which are subject to both an external blowlamp and internal combustion heat. External spalling is the biggest issue I think. The original drawings call for EN51 which appears to be moribund and without a close equivalent.



Any suggestions for an available material please?


In article , Roland Craven writes

I could not find any details for EN51, but the attached site contains some useful information on translating obsolete EN numbers into modern equivalents, and some useful links to other sites. I'm sure there must be a more comprehensive list somewhere - if anyone knows of one (free - we hobbyists can't afford to pay ludicrous prices for standards documents!) do please pass it on.

David

Roland

Preume you've found this:-

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and

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Which gives 16 MnCr5 as an 'equivalent', which is a case hardening steel, which cross-references again to AISI 5120H which looks like something between EN32 and EN36.

Maybe

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would be able to help?

Cheers Tim

I would have thought that IC engine valve steels would be ideal. EN52B non stainless inlet valve steel or 21/4N austenitic stainless exhaust valve steel which can cope with even higher temperatures and stresses.

My thanks for all the replies (on and off group). I should perhaps have said that I have a copy of BS970 1955 and a MacCreadys full catalogue which I have studied at length. Those with a similar level of Ni had much higher levels of Mo and/or Cr and I have no idea what impact those differences might have.

High Cr content provides very good resistance to scaling which was one of the reasons for the development of 21/4N exhaust valve steel with c20% Cr. However even EN52B has 8-10% Cr and both steels are very resistant to corrosion and scaling in a combustion chamber environment. They are also readily available although primarily in smaller diameters to suit valve stems. I guess you get some pretty big valve stems in ship engines though so I can't see anything you need to buy being a problem.

I have plenty of scrap valves in stem diameters up to 9mm if you want to play with a couple. You don't say what size these things are.

PS, you might want to look up G&S Valves Ltd on'th Interweb. They buy those steels by the ton so they'll have good deals with the best suppliers and might be able to get a chunk in a size bigger than they usually use a lot cheaper than you going along to a steel stockist for a one off purchase. They might even have some scrap FOC that'll do you.

The older Macready's catalogue lists EN51 as 3% Nickel, 'Valve Steel' and gives SAE2330 as an equivalent.

HTH

Peter

-- Peter & Rita Forbes Email: snipped-for-privacy@easynet.co.uk Web:

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Thanks Dave/Tim/Peter. That makes sense and I'll give it a whirl. I need

11/16" stock so I'll just go ahead and get a bit. or the small quantities I need its not worth phaffing about with scrap. In fact I just went and looked at the (colour coded) bar- ends a fishing friend donates and I have some 16mm in stock :-)

thanks to all Roland

In England, public libraries can usually obtain a wide variety of standard documents, sometimes under quite absurd conditions; for example to look at BS 978 Part I, they had to print it out from a computer system and I had to sign a document stating that I was required to look at the printout in the library and keep away from any copying machines, and to ensure the printout was returned for destruction after I had finished. I was allowed to take detailed notes longhand!

However, I got the information I needed at no cost!

Alan

I used to find the BSI library in Milton Keynes very useful. Unfortunately they moved it to somewhere on the M4 corridor so it's of no use to me anymore - but worth a try if you're in that part of the world.

-adrian

I'm amazed and delighted to hear G&S are still going. I used them when I was doing lots of old Brit bikes and they were very helpful then (15~20 years ago) Richard

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