circular saw drill bit??

Starrett is a trade name for them, try that in the search

If you try earching for a hole saw, then Screwfix do have them, if that is what you are after. So do Axmister Power Tools, and poibly a bigger choice:

Thanks for the input, but these are hole saws. I need to cut a line (linear) not a hole. Does anybody know what these are called.

thx

You can get a saw blade that would chuck in an arbor, which would cut a straight line, however the exposed saw blade would be very dangerous, and I would not recommend it! If the blade got wrenched at peed the results might be an awful lot of blood. For this sort of job, if you have got the money, a Fein Multimaster has special saw blades, the multimaster oscillates, it doesn't whizz round. You used to be able to get a drill attachment from Wolfcraft and some others, that give some protection from the blade. I haven't seen one for years though.

If all you want to do is cut a straight line in 3mm plywood, what is wrong with a fine handsaw? Much more controllable and safe! Bahco make one like a tenon aw with no back, B&Q keep these.

John

I wonder if you mean a spiral bit type of cutter -like a straight router cutter bit - you would be better off with a router than a drill, cheap router maybe 15 quid. See

=================================== Is this what you're describing?

Yes, that's it - thanks a lot for your help :-))

================================== I'm not sure what you intend doing but they're not really very safe for free-hand use. I use mine occasionally in a drill press with rather limited cutting possible but I doubt if this is what you have in mind.

Cic.

I will be cutting away plywood from around the perimeter of a stud wall along the floor - can't think of a better way to do it.

I bought one today and it did the job perfectly :-) I was able to cut through lino and 3mm plywood around the base of a stud wall (the ply was under the floor)

Thanks again for your help