when not to use mild steel ?

Couldn't they make it any more complicated than that? Or harder to remember?

This is why the EN system was created in the first place!

Michael W

In my experience, very few stockholders use the euro-labelling:

**LINK**

I have never had any problems just relying on a a handful of EN steels.

Neil

I make a lot of motorcycle parts, wheel spindles from EN16T/nuts and bolts from EN24T also some from 304 stainless. I use mild steel a lot for my fixtures as it is cheap, good enough to do the job and readily available.

I have this year made patterns and got castings made for a new lathe cross slide, a swivelling/tilting angle plate (patterns made by Bro in law) and a ball turning attachment. The cast iron parts machined up very well and are the right materiel for the job. Throw in a fair bit of aluminium (lots of grades enough for a separate post to discuss) and a bit of bronze that is about all the areas covered.

Thats interesting, now we have black EN8, bright EN8, & engineering grade EN8.!

Any one know what S275 is ?

Edited By bodge on 03/10/2016 10:29:14

S275 is a structural grade general purpose steel. Can't remeber the other names for it but it is readily available in sheet, strip and bar.

Mark

.

A few months ago when a steel plant was closing and there was outrage and examination as to the reasons why, one on the main causes was the price of the products not being low enough on the international market.

The Chinese for e.g. were placing very heavy import duties on what they termed as 'technical steel' from the UK. - What is or what category's of steels are classed as 'technical steel' ???

Just curious, Nick

EN tells you absolutely nothing, it's just a number. At least the BS970:1991 classification tells you something about the composition of the steel, 070M20 is 0.7% manganese, 0.2% carbon. If a stockholder doesn't understand a spec which is only 25 years old, perhaps you shouldn't deal with him.

My early visits to my local steel supplier were more painful than they needed to be because I spoke "Metric, International Standards" and they spoke "Imperial - WW2 Emergency".

After they realised I was a serious repeat customer we began to communicate and I was able to ask the manager what was going on. "It's our customers "he said, "they don't understand or want anything new. I have to supply what they ask for."

I imagine up-to-date, bright-eyed, bushy tailed young chaps joining industry from college only to find they are working for traditionalists. These are the chaps who believe that anything since Whitworth was a backward step, evil, foreign, cheap, nasty and the reason we lost the Empire. Naturally enough, bright young men in such an environment will gradually fall in-line, eventually themselves becoming hide-bound just in time to correct the foolish modern ideas of the next generation.

Please tell me I'm wrong! I don't suppose Rolls-Royce work that way, but what about the small fry...

Dave

Technical steel ? hmm, Just another name for Protectionism I think.

bodge, Mark C is correct s275 is plain structural steel, ie UB's, UC's, SHS ect. That is the type most specified by Structural engineers in UK for buildings. . s355 is another Structural steel but stronger, specified for heavier loaded UB's ect. The numbers are to do with the minimum yield strength in N / mm ². There are quite a few other grades, but these are the most common used in the building industry. Also available in plates ect.

Possibly a bit extreme. The EN 10027 std is a lot more specific than the noddy grade descriptions at the likes of Metal Supermarket, like "EN8" or "304".

The actual description used on the drawings tends to depend on the customer, so in China the grades are often JIS (sort of the default), EN (European) or DIN (for German customers).

I expect the "technical steel" subject to duty will be defined on a (black)list but in practice I suspect this will basically mean high value, specialist alloys, rather than bread and butter commodity steels.

PS, the EN stds are copyright but they seem to be visible with little search effort.

Edited By Muzzer on 03/10/2016 13:49:39

I'm afraid you're wrong. No self-respecting "up-to-date, bright-eyed, bushy tailed young chap" would be seen dead in engineering. Instead they're in marketing with a nice new MBA, and leave all that boring, tedious technical stuff to the oldies.

Andrew

PS: I don't suppose that many of the materials that Rolls-Royce use are likely to be available from your average steel stockholder.

It's the range of high-performance alloy steels used in power-stations, Aerospace, Defence and similar. It ranges out to include materials like Inconel, which has less than 10% iron in it, and isn't what I think of as 'steel' at all.

The West doesn't compete well with "BRIC" countries when it comes to mass-production of cheap commodity steels for car-making and construction, but we are still ahead with the expensive high-tech stuff.

It's hard to decode what the Chinese are up to but my guess is that they are simply trying to encourage their own industry to improve their capability to make high-end steels. Doing so would have commercial and Defence advantages. It's possible that the move is a military requirement intended to guarantee internal and export supply in the event of sanctions being applied by the West.

Dave

I thought Metrification was bad enough! I'll stick with 1018, 4140, and 12L15 steel thank You.

EN8M ( 212M36 ) Might be an interesting one to add. It's roughly twice as strong as mild steel and the yield stress is higher. It a free machining version of EN8. I was curious as some one mentioned it earlier. It's through hardening as well but wont be the same as silver steel in terms of cutting edges.

I think EN3 is the old case hardenable mild steel but I've seen comments that the none leaded free cutting can also be case hardened.

Steel used to be supplied by name or a supplier of good quality stuff. The numbers are more sensible but trying to find equivalents is difficult. Another very popular steel was KE805 used for all sorts of things but assuming I have the analysis correct lowish nickel chrome steel there doesn't seem to be anything similar other than 817M40T. There is also another version that is more tensile. 826M40 but probably more of a pig to machine. KE805 wasn't too bad.

John

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I fear this thread or topic may becoming one of those infamous "Sirens".

Edited By Michael Walters on 03/10/2016 14:29:56

KE numbers are specific to Kaiser Ellison (now defunct). Used to use lots of KE672 which was along the lines of GP (gauge plate).

Mark

Steel is a generic term for an almost limitless of variety of iron based alloys.

According to Total Materia, their database contains the details of more than 230,000 grades.

Shock horror; it costs money to research the many varieties of steel that are available for industrial use. It's a good job we Model Engineers only have to deal with a few of them.

There is some one machining O1 here. Mixed results so suspect it could good be once machining is sorted. Needs skipping in places.

Edited By Ajohnw on 03/10/2016 20:41:06

Edited By Ajohnw on 03/10/2016 20:41:42

Speed looks too low and lacking feed rate/cut to me - chips are not taking the heat away (blue) and not breaking properly - not working the insert enough (it could be blunt also but can't see).

Oxy would be my preferred method for that job - you want the end hot in a hurry with the rest staying cool. O1 is oil hardening so agitated dip in oil is correct followed by tempering. Proof is in the eating or so they say, he seems to be cutting nicely in the final shot.....

D2 or A2 would also be OK for tooling. D2 will air harden as will the A 2 (A=Air hardening, O=Oil hardening, D=High Carbon & Chrome). D2 is very nice to machine and maintains good dimensional stability when heat treated. Best sent for vacuum heat treatment - comes back all nice and clean with a pleasing "precision engineered" look to it (if you did a good job machining it! ).

Mark