Funny enough I'm having a similar problem, not rads just old pipes I need to remove. Been my carry on plumbing here what with first the stop value locked up so could cut of the water in the house, then finding the one outside and discovering the tap was more than an arms length down, then more or less guessing which 2 of 3 pipes I could remove, tapping the end of the other. Then then I could find either of the 2 pipe cutters I have and the hack saw broke. Ended up using a the jig saw but only had a worn out wood blade - very very churky if you are interested. Did 3 cuts with that before it snapped so still need to cut the pipes the loft before I can remove them. Order in for more jigsaw blades from Amazon but even then 6 out the last 8 orders from them have gone elsewhere ?
Fun & games, good luck mate.