If a Quorn builder can produce a 3/4" dia steel ball with a carbon steel form tool then I think it entirely possible.

I produced ten steel wheels of 3 3/4 inch on my mini lathe by not using a form tool. Unless you really want to produce the form there is little to be gained by being too picky in my opinion. But if you do want to use a form tool only use it to do the final finishing.

+1 to Duncan's reply. I used a round-nose tool of the correct radius fed up the 3 degree angle until the diameter at the root of the flange was correct, then fed down the 20 degree angle until a smooth transition was obtained. The radius C was achieved using files and a template to check progress. It was slow and somewhat tedious but enjoyable at the same time. I only had 8 to do, each one took maybe an hour after the castings had already been turned roughly to size. Was my first attempt so someone more experienced could no doubt do it faster.

You haven't said what kind of lathe you have got. If it's a 16" swing Monarch or DSG, Colchester etc etc the full-width form tool would be the quickest way. But a Chinese mini lathe will most likely chatter like a garrulous matron at a christening. I wouldn't try it on my Myford either, for the same reason.

Perhaps worth mentioning that Professor Chaddock (see my earlier post) mounted his tool upside down in the rear tool post. His lathe was "light" and "elderly", a Drummond i think.

Ron:

I will just add that Professor Chaddock found that his three jaw chuck slipped under the load imposed on the work by the form tool but I imagine that your wheels will be secured to the faceplate and trust you won't have this problem.

Good luck!

There doesn't seem to be an 'Emergency Number' grade equivalent to S275.

EN steels have an interesting history. During WW2 the UK government found it necessary to discipline British Steel producers, each of whom wanted to do their own thing. Government set specifications for all the common steels in a 'War Emergency British Standard Specification' (BS970), and mandated it. So rather than having six or seven mild-steels similar to EN3, there was only one. This useful simplification caught on after WW2 and people still order some steels by Emergency Number today, even though the system was phased out fifty years ago. Although it may not matter, there's some uncertainty today about what an 'EN' steel actually is. Whilst 'EN3' bought today might meet the 1941 specification, it could be a modern equivalent.

The most obvious difference between the EN system and modern steel specifications is EN doesn't demand very high accuracy of the mix. Sensible given production methods in 1940, but modern steel specifications are tighter.

S275 is a low-carbon steel improved with a dash of Manganese. It's one of the mild-steels outstandingly useful for structural and basic metal-work: cheap, reasonably strong, and easily sawn, drilled, machined and welded. For ordinary general purpose structural and mechanical engineering – 'Parts that will not be subject to high-stress.'

Judging by it's constituents, S275 is similar to EN3 except it's more tightly specified (less variation.) It contains slightly more Carbon and noticeably more Manganese: it should be stronger. Some variants also contain Copper to improve corrosion resistance. In a home workshop I doubt there's much difference between EN3 and S275.

Dave