The HO code 100 Peco Setrack series ST 244 and 245 curved turnout has an outside radius of approx’ 22" inside radius of approx’ 18".
Their Streamline series SL 86 and 87 curved turnout has an outside radius of approx’ 60" and inside approx’ 30".
If you are interested in ordering some I would suggest that you order from Hattons in the UK, you will save a lot of money if your order is large enough to offset the shipping cost. That is where I plan to get my next order of Peco’s from. Peco are way over priced in the U.S.