Vedkap (en vedkap, vedkapen) is translated as 'circular saw' in my dictionary, but it is not any circular saw, it is a rough one for cutting off suitable lengths of firewood. The tool can also be called just kapa (en kapa, kapan). Ved is 'wood' of course, and the verb att kapa means ‘to cut off, a loan from Low German. An ordinary circular saw is called … en cirkelsåg.
Att kapa also means 'to hijack' a ship or a plane. That is a loan from Dutch, and probably unrelated. Kapare is ‘hijacker’, ‘pirate’