What type of STEEL?

[chris stephensParticipant @chrisstephens63393]

Hi Ian,

EN8 is, depending on suffixes, 1042 or 1040. 4140 is, and I quote, EN19 a 1%chrome/moly steel which is a “direct hardening steel”.  

I don’t know about the rest of you guys but I think nice simple to remember  EN numbers are much better for our end of the market than the new 3 number, one letter and 2 more numbers, which are easy to misremember and cock up. Do we home bodgers really need to know the “exact” chemical composition of the steel we are using for our Black 5 forward giggle pin and housing. 

chriStephens

[Martin WParticipant @martinw]

Hi

 

I hope this post will help with the original query regarding steels etc without getting into the esoterics of composition and off beat applications.  The following reference gives both the EN (emergency number) plus the BS number series of various steels plus notes on their cutting and application characteristics.

 

http://www.roymech.co.uk/Useful_Tables/Matter/Strength_st.htm

 

I have found this quite useful reference especially as I am a relative newbie to the hobby. This site covers a wide range of materials plus a lot of other useful, well to me it is, data.

 

I hope this will help James, who like myself, and others find the array of available materials somewhat confusing.

 

Also to muddy the waters further standardisation has now re-introduced the EN prefix as the European Numbering plus a range of numbers and suffixes. However this numbering system has a raft of numbers after the EN prefix so it is easily distinguished from the Emergency Numbering prefix introduced sometime in the 1930/40s. 

Cheers

 

 

Martin W

Edited By Martin W on 07/03/2010 16:49:32

Edited By Martin W on 07/03/2010 16:55:08

[macmarchParticipant @macmarch]

Ramon, A trip to Peterborough? are you far from me in March?

[CirclipParticipant @circlip]

Gee, thanks for that link Martin W, will have to bookmark it

[Martin WParticipant @martinw]

Hi Circlip

 

Missed  the link in your post on the previous page OOPS. Still never mind  eh! Some else might only read the later posts and pick it up!!!

 

 

Cheers

[Nigel McBurney 1Participant @nigelmcburney1]

Hi I have tried hardening en8 when making cam follower rollers for a full size vintage stationary engine,accepting that the heating via propane is not the best method, the rollers were hard enough for the purpose but nowhere near as hard as say gauge plate or silver steel.plus there was a lot of shrinkage, I made the rollers then made the shafts to suit.

regards 

[Ramon WilsonParticipant @ramonwilson3]

Ray (Macmarch)

I’m afraid I’m not.

I’m at Beccles in Suffolk so Peterborough is a good 200 mile round trip! Usually come up once a year though.

[James VeitchParticipant @jamesveitch82153]

Hello All,

A couple of things.  Versaboss suggests a MEW article on steel types and metals would be a waste of time.  To those who know, yes, to those who don’t know, no.  I’m not suggesting a comprehensive catalog of code numbers, I’m suggesting basic guidance for newbies.  I guess the editor needs to decide what type of article will service the greater part of the subscribers. 

The link to the RoyMech steel page given by Martin W is interesting but still confusing to a person of my experience.  For example the term “silver steel” doesn’t appear on that comprehensive list.  I suspect terms like “silver steel” and many others that are bantered about are applied to a whole range of metal recipes. 

Thank you Nigel McBurney for introducing a new term to me, i.e., gauge plate…???

 A bit off topic but still in the ball park, Ramon mentions heat treating EN8 with “through hardening” and Chris mentions “direct hardening” EN19.  Two terms I haven’t heard of before.  I’m still looking for a small book that tells me to do some simple examinations on a hunk of metal (like the geology field test) and then use it for and machine it within general parameters.

Now for a personal anecdote.   My brother-in-law used to be a statistician for the metallurgists at the old BHP plant in Newcastle, Australia.  He would relate how it was the devil’s own nightmare to get any batch of steel within specifications.  You just never start with a pot of pure Fe (iron) and you can never make it totally pure.  So every batch of steel that rolls out the door is the best approximation given the raw materials that rolled in the door.  To me that all made sense.  Everyone is trying to do their best, but a good engineer examines the material at hand for compliance to specifications.  I don’t think that any given specimen of EN8 or EN…whatever completely meets all specifications.  As a novice I’m interested in general classes of metals.  How to define my metal need for a particular job, how to identify a generally suitable specimen, how to generally deal with that metal.

 

I once again thank all those who have made comments to my questions, you are helpful and I appreciate the time and thought you have given.

Yours, Jim V.

[Ian S CParticipant @iansc]

Thanks Chris for the specs. Ian S C

[Ramon WilsonParticipant @ramonwilson3]

James,

For the home user steels are usually heat treated in two basic manners – ‘through hardening’ and ‘case hardening’. Keeping it basic then —

 

In the first, the metal, after heat treatment, is as it says hardened completely through the part. This then requires ‘tempering’ to reduce any tendency for brittleness and to reduce the hardness to the level required for the application of that part. The kind of steels normally encountered for this are silver steel and gauge plate though you can of course now add EN8 to this

[‘Silver steel’ is not a generic term. It is what it is. Keeping this ‘practical’, as already said, this comes as a very bright ground finish. It normally comes in 13″ lengths (though it is available in longer) and sometimes, though not always, it is marked ‘Stubbs’ on the end.  Ground mild steel round bar can, to the inexperienced, be visually mistaken for it. The easy test then is as someone has already commented is carrying out a ‘spark test’ or better – taking a thin slice and quickly heat treating it – the result will quickly indicate which you have]

 

 

In the second method the part is encased in a compound which is high in carbon and then heated. The carbon deposits into the surface of the part, the longer it is held (at temperature) in the compound the greater the depth of the ‘skin’ but this is usually only a few thou. Hence the term ‘Case Hardening’. The hardess of the skin is usually left as quenched the core of the part remaining ductile though this can be further heat treated if desired. The steel has to be suitable for this process – the (very) limited amount I have carried out using this method was using EN32b.

 

There have been several books written on the heat treatment of steels for the home user all of which will give you sufficient detailed information as to what is occuring as you carry out these proccesses as well as how to carry out it out at home

 

There are of course many other ways of hardening metals but these are really well outside the needs of the home practitioner

 

Hope this helps- Ramon

[Sub MandrelParticipant @submandrel]

Tubal Cain’s “Model Engineer’s Handbook” has a really good diagram on the spark test. Perhaps David could get permission from Tom Walshaw’s widow to publish it in MEW?

 

My understanding is that EN8 is suitable for use without further heat treatment?

 

If you want tough but machinable steel EN24T is the stuff to use (it has been pointed out to me that the ‘T’ for ‘tempered’ is vital.

 

I went to metal supermarket today  and all their stock was marked with old EN numbers, except the silver steel and ground flat stock.

 

Neil

[Author]

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