Are you stuck with hundreds of plastic library cassettes full of drill bits but whenever you open them the one bit you need is missing or broken? Are you starting out in DIY and just want to know what drill bits you need? Hopefully this will be of some help to you. This is an evolving article. I’ve changed my mind what needs to be in it about 150 times now. For the moment I’m settled on these drill bits and I’m comfortable with that.
Introduction
I’m not going to give you a history of drill bits or anything, don’t worry. I own literally hundreds if not thousands of drill bits. They accumulate over time and since they don’t take up much space they’re the perfect item to hoard. I have an unrealistic expectation of sitting on a rainy day and sharpening them all. Cleaning all the rust off them and perhaps sorting them in size order. In 45 years that day hasn’t come yet… but just you wait.
By the way, as per usual I need to pay the bills and I’m not providing Amazon or Ebay with advertising for free. So, reluctantly, this article contains affiliate links to products I would consider buying – you can read more about affiliate links here. I would always encourage you to support local smaller businesses rather than the global conglomerates, but if you insist on using them then please use my links – Mr Bezos can afford the hit. I’m actively working to kick both Amazon and Ebay in to touch but until smaller retailers catch up with affiliate marketing my options are a bit limited. Bear with me – I’m on it! Enough rambling, let’s cut to the chase.
HSS drill bits
I have literally hundreds of bog standard HSS drill bits of vastly varying quality and sharpness. Here’s the sizes I use all the time. Please note if you use the links below you’ll need to tell Amazon what size you want:
- 2mm – generally for pilot and starter holes
- 3mm – pilot holes and starter holes in steel
- 4.8mm with depth stop – for shelf pin holes
- 5mm – general purpose and M5 bolt holes
- 12mm – nice sharp DeWalt Extreme bit for cable holes
- Drill depth stops are a handy addition to your collection!

Having a nice 12mm bit such as the DeWalt Extreme below is very handy for cable holes an the like – for example coax aerial cables through cabinets:

Masonry bits
These are the sizes of masonry bits I use all the time. I treated myself to some nice new Bosch Multi Construction TCT bits in 5-8mm. For whatever reason the pack doesn’t include a 7mm bit but you can buy that separately if you need one. As I generally use Fischer plugs I rarely need a 7mm masonry bit. I’ve also got an old 10mm bit that I sometimes use for CoreFix fittings etc. but in all honesty at that size I’d generally use the SDS.
- 5mm – for yellow plugs
- 6mm – for red plugs, DuoPower 6mm etc.
- 7mm – for some brown plugs
- 8mm – for the brown plugs I use and molly bolts
- 10mm – for CoreFix fittings

Tile bits, countersink bits etc.
It’s always handy to have a couple of tile bits – note that these are only suitable for ceramic tiles and they’re no use for porcelain! Porcelain is a nightmare to drill and not something I’m covering in this article. The 6mm bit gets used the most for bog standard red plugs and then I’ve got the 10mm one for tiles on hollow walls.

Spade bits – DeWalt Tri Flutes
DeWalt tri flutes seem to be the optimal cross between a spade bit and an auger bit. Spade bits aren’t the most elegant drilling solution and easily get jammed. Auger bits can sometimes screw their way in to the wood without actually making a hole. Tri flutes have three cutting spurs and seem to give the best of both worlds – rapid drilling, clean holes and the bits stay sharp for much longer. Plus a full screw tip that pulls its way in to the wood more easily.

The sizes I generally use are 16 & 25mm (for pipes) but it was cheaper to buy a three pack which also included a 20mm bit.
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