So my Masterlock bike lock failed this morning, leaving both my bikes chained to the wall anchor. Had to get the bus in! So I need to cut the chain off. It's 8mm hardened steel. Good excuse to get a Dremel as I've a few other jobs that need one. So would the cheapo 200-5 be good enough? The cutting disc supplied with it says it's OK for hardened steel. Or would I be better off getting the 3000/4000?