Plan the holes, then the bits
The easiest way to overspend on bits is to buy them one at a time in the middle of a project. The easiest way to underspend is to rely on one bit for everything. A better approach is to list the holes you expect before you shop, then match the list to bits you already own.
Take a sheet of paper and write down every hole the project needs. For each one, note the material, the diameter, the depth and whether the surface will be visible. This is a short exercise, and it usually reveals that a project needs only a handful of distinct bits.
A worked example (hypothetical)
Imagine a simple plywood and pine bookshelf with screwed joints, adjustable shelf-pin holes and a few wall fasteners. These sizes are examples, not a specification.
| Hole | Material | Likely bit |
|---|---|---|
| Screw pilots | Pine | Small twist bit sized to the screw core |
| Screw clearance | Pine | Slightly larger twist bit |
| Screw head recess | Pine | Countersink bit |
| Shelf-pin holes | Plywood | Brad-point bit matched to the pin |
| Wall anchors | Drywall or masonry | Bit sized to the anchor, masonry bit if needed |
That is five holes and roughly four to six bits. If a bit appears on your list twice, you can drill many holes with it, which tells you it is worth owning a good one.
Building a small starter kit
For general household and light woodworking use, a modest kit usually covers most tasks:
- A set of twist bits in small fractional sizes for pilots and metal.
- A few brad-point bits in common sizes for clean wood holes.
- A countersink bit, or a combination pilot-and-countersink bit.
- One or two spade bits for rough, larger holes in framing.
- A small masonry set if you ever hang things on brick or concrete.
- A driver bit set for screws, which is a separate category from drill bits but often lives in the same case.
If you mostly drive screws, you may use drill bits less often than you expect. The difference of drill versus driver is worth understanding when you decide what to put in the kit.
Which sizes are worth buying individually
Sets include many sizes, but some sizes get used far more than others. Single bits are sensible when:
- A size you use constantly wears out. The small bits for pilots are the first to dull or snap, and replacing them individually is cheaper than a whole new set.
- A project needs one oversize hole. A single large spade, Forstner or hole saw may be all you ever need in that diameter.
- You need a specific match. Shelf-pin holes, dowels, hinge cups and hardware often require an exact diameter. Check the hardware before buying.
- Quality matters for that bit. A sharp, well-made brad-point or a hard-metal bit is often better bought on its own than as one of dozens in a set.
Anchors and fasteners come with their own requirements. Wall anchors, for example, usually specify the hole size and sometimes the type of bit, so read the package before drilling.
Do not forget the supporting items
A good bit still needs help from the rest of the setup:
- A cordless drill with adjustable speed. A drill press is helpful for repeatable depths and square holes.
- Clamps and scrap wood to back the exit side.
- A depth stop or a piece of tape.
- Cutting oil for metal.
- Safety glasses, hearing protection where the noise is high, and a dust mask for masonry or sanding-heavy work.
Scale to the project
A one-off hole in a wall may need just one masonry bit. A cabinet or deck build may need a dozen different holes across several materials. A metal fabrication project calls for sharp HSS or cobalt bits, lubricant and a firm clamp setup.
If you are unsure, buy for the first stage of the project, finish it, and add the next bit when you know you need it. Keep the packaging or note the size you bought, since small bits are easy to mislabel once they are mixed in a case.
Project needs, materials and tools vary, so use this plan as a starting point and follow the instructions that come with your hardware and your drill.