Bosch 7x EXPERT Self Cut Speed Spade Drill Bit Set (for Softwood, Particleboard, Ø 16-32 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.

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!

I was working blind cutting through a joist that was set way back in a timbered ceiling. Only access to ceiling cavity was from my garage. Bosch tool located and cut through heavyweight joist in around ten minutes

These are awesome! They cut through wood like a hot knife through butter.

while it is very fast at drilling, it leaves a very rough hole

Self cut seems to refer to the fact that there is a thread on the leading point. I didn’t want this but it wasn’t made clear enough that this was the case. When drilling out a hole in plastic, for example, the target has to be held down quite firmly to stop it spinning around.

Combined with an impact driver, these bits are amazing! They just pull themselves through the wood with no pressure needed. Fast, clean cut and so much easier than a standard spade bit!

Really good, stick them in an impact driver (lots of noise) or a drill and goes through any wood I've tried in seconds