Bosch 1x EXPERT Self Cut Speed Spade Drill Bit (for Softwood, Particleboard, Ø 6.00 mm, Professional Accessory Rotary Drill/Drivers)

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.

Here's a tip to make holes that are clean on both sides.Drill a pilot hole with a small and normal drill bit through your material. Doesn't have to be big, a small one is fine.Use this drill bit on one side using the pilot hole as a guide. Don't go all the way through.Then when you are close to going through, turn it around and go through on the opposite side. Perfect hole every time. No splintering like you see in the pictures. They are just doing it wrong.

These are the best spade bits I have used, they work rapidly when new, the don’t seem to lost super long but they are definitely some of the best out there. Just be careful as always not to hit metal lol.

Forget all the ads for fancy multi toothed drill bits.These are superb. They have a screw head that drives the tip of the drill into the wood as it cuts, so you get a fast cut, secure and accurate hole every time.I wish I had these years ago.

Great value

Great cutting bit. Drilled through 3inch timber with ease.

Definitely self drilling! So much so you really have to watch it as it can really pull into the wood! Sometimes a bit too much!

16mm was missing and got two 18mm instead. They cut very well and stay sharp