Posted by Clive Foster on 27/12/2022 10:05:42:
The major problem for folk like us is that no-one has made EN steels for donkeys years.
What you get when ordering by EN numbers is your suppliers interpretation of a steel with sufficiently similar properties to be considered equivalent….
Confusion abounds, and poor old grandad, not realising he's bought the wrong specification, is liable to assume all modern steel is of inferior quality. Steel was wonderful when I was a boy.
A quick look at five UK web suppliers revealed that when asked for EN1a they provide 230M07, a steel in which free-cutting is achieved by adding Sulphur and Lead. 230M07 is a common substitution, therefore, folk are liable to believe EN1a contains Lead. Unfortunately it's not guaranteed. The original EN1A of 1955 was free-cutting due to Sulphur, with no Lead. Modern equivalents of this variant are also supplied as 'EN1A'.
Sulphur only 'EN1A' is noticeably more free-cutting than ordinary mild-steels and Leaded EN1A machines even better. However, unleaded sulphur only EN1A is cheaper, slightly stronger, and easier to weld, though the finish may be a little rough. Against that, cutting tools last longer on Leaded EN1A and there are fewer finish rejects. In industry, the most appropriate alloy is thoughtfully chosen by the designer or production engineer. What's the cheapest way of meeting requirements? Not 'I think I know what EN1A is!'
We're stuck with EN numbers because they've become a bad habit. Large numbers of untrained users and local metal emporia passed the system down through the generations. The internet is starting to break EN numbers because an online shop doesn't depend on prejudices – it can say what the alloy really is! I expect it will still take several decades though…
Dave
Dave