I needed a piece of metal to make the flywheel for my Ford Quadricycle model and went to my favourite metal supplier, as they had 5"dia m.s. steel bar they they would cut off the 1" piece that I needed.
I had an apologetic email back to say that they couldn't supply as their saw was broken.
I had a search around and came up with ;
http://www.ebay.co.uk/usr/steelcitygav?_trksid=p2060353.m2749.l2754
Who had 120mm dia (just under 4 3/4"
and would supply a 1" inch slice in EN3.
This would mean even less machining so I ordered it at a very reasonable price incl delivery of just over £13.
I will certainly be using them again and will collect when the present troubles are over as they are about 1/2 an hour away from me.
Brian