The 50mm stock thickness may be too much for this option but myself and many others cut through aluminium sections etc with a chopsaw (TCT blade - not wood blade!). This gives pretty straight cuts.

I think Jazz mentioned a table saw with TCT blade but then 50mm may be getting too thick, not sure.

There is a pretty large, industrial gauge horizontal saw at work, similar in concept to the one Clive linked to but chunkier. The cuts are nowhere near straight so cost is no guarantee of cut. Having said that it probably needs an overhaul.