tube / pipe fit over scaffold tube

Hello all

I did ask this on another newsgroup a month ago - but not their thing.

I want to find a tube / pipe, readily available, which will slide over a scaffold tube. For making jigs and fittings from offcuts of scaffold tube.

Here in the UK (don't know about elsewhere), scaffold tube has 48.3mm outside diameter.

I did some web-searching and find, for example, that NPS 2 schedule

80, with 60.33mm outside diameter and 5.537mm wall thickness, should give 49.256mm bore.

Weld on "fins" with holes for bolts, slit between the "fins" and bolt-up, and the tube will contract and grip a scaffold tube???

Any knowledge on this?

Regards, Rich S