My small lathe belt broke and I used a vacuum cleaner belt - it was circular in section but is still doing the job some considerable time later ( and they only cost me 50p )so might be worth a try.
Sorry,just realised you want a .5m belt which is bigger than a vacuum cleaner- what about an altenator belt for a car?
Edited By TinPot Pilot on 05/05/2012 22:17:07
Edited By TinPot Pilot on 05/05/2012 22:20:37