core drill guide bits

[Fred]

Perhaps with it being a blue bosch, it is rated to 68mm cores in regular, daily, use by a tradesman. Perhaps for once a year DIY drilling the drill would cope with a big core now and again?

[js.b1]

If you are drilling "conventional" brick an old 480W non-SDS drill will do 107mm, gets hot, but just about does it. Will not even get a

152mm going re torque of course (tried, it died, hireshop visited).

So a 850W SDS run in non-SDS mode with lower RPM and potentially higher torque should do 107mm without much difficulty in "conventional" brick.

Conversely if you have hard engineering brick, which will take hours, forget it - and you need a better bit than the generics if it does more sparking than drilling.