I drilled 4mm pilot hole to locate the centre of the exit hole. I drilledinto the exit hole 10mm then went to the original hole and drilled through stopping the drill BEFORE withdrawing the drill bit. An almost perfect edged hole was the result. The quality of the drill bit is very good and made it easy to achieve a good result quickly.

Some of the review categories are a bit strange in my view so didnt score them. But overall, feels good quality for the price. Used for bird boxes, not sure what i will use it for going forward mind up! But my little lad wanted to build bird boxes so bird boxes we built!. It was still sharp after drilling out 2 boxes.

only part way through my second hole did I realise how these work properly. I read the blurb and watched the videos but it needs to actually happen for you to understand it. The threaded tip has to bite into the wood and pull the bit through. This means it goes through the wood MUCH faster than a standard spade bit. however as it does this the side points engage – which is where the speed comes from – at this point a lot of torque is needed to keep it moving otherwise it jams. drilling through joists with the 30mm bit requires some force to get the thread to engage and then a lot of strength to hold the drill against the torque , particularly worse when also using a right angle adapter. hard to find the right balance of slow speed (control, not jamming, handle the torque) and just fast enough to pull through . But with the right torque and right speed and hold just the right amount of pressure, it was probably 10x faster than previously drilling the same distance through a joist with a “normal” spade bit.

don’t use them for anything other than wood. holes in plastic sheets or pipes, use something else.