The problem you have is your required internal dimension is too close to what is known a ‘nominal bore’, in your case 1” nb. Any pipe/tube you find around that size will be just over 25mm ID, so you have no material left for a finish cut.
See *bay 221896041212 to see what I mean.

You may have more luck finding a tube more designed for structural uses than fluid transfer, race car cages, kart chassis etc.