How To Choose The Right Drill Bit

By HomeAdvisor

Updated February 28, 2017

DIY or Hire a Guy scale

Figuring out which bit to use for your project can be tricky – and sometimes best left to the experts. Use this guide to help you decide whether you’ll DIY or hire a guy.

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Materials Required:

  • Surface to drill into
  • Safety glasses
  • Electric drill
  • Bit set – including masonry, wood drill and forstner bits
  • Gloves

HomeAdvisor Tip:

If you’re just getting started, buy a standard drill. It will give you plenty of options.


More Info About Selecting Drill Bits

A drill is one of the most indispensable tools you can have in your arsenal. Whether you’re a committed DIYer or a weekend home improvement warrior, you’ll probably use a drill more than you’ll use any other basic power tool. The drill’s versatility is afforded by various attachable bits — each uniquely suited to a particular material or job. Bits can be intimidating. Getting to know the different types available will help you choose the right one.

Choosing Drill Bits by Type

Drill bits are first organized according to the medium on which they can be used, then by material. This is why you will find bits labeled for use on wood, masonry and metal. Once you’ve identified your medium and material, you’ll select the size that suits your particular needs.

  • Wood Drill Bits: These can be identified by a small, pointed tip at the very end. If you look closely, you can see spurs on each side. These grab wood and carve it away. Steel bits are great for softwood varieties; hardwoods will eventually dull them. Titanium-coated wood drill bits last longest. The wood drill bit is the most versatile and commonly used bit.
  • Masonry Drill Bits: These bits have a gently sloping tip. Sometimes, the tip of masonry bits is coated in carbide, which prolongs their sharpness. A masonry bit works best with stone and cinder block, and it can work well with some tile as well. It’s highly durable and — with a lot of effort — will get your favorite photo hung on a tough surface like a brick wall.
  • Metal Drill Bits: These have a wide-angled point at the end, and they may also be painted black. If you are buying new metal drill bits, look for a label with the name high speed steel (HSS). These bits are highly versatile. More expensive metal bits may have a titanium coating or contain cobalt. Steel bits will drill through soft aluminum, though high-speed steel is required for other metal types.

How to Choose Drill Bits by Size

Drill bits come with pilot hole charts that will help you identify the right bit for the job. These charts are based on the shank of the screw and are meant to be used only as guidelines:

  • Use a bit 1/64” smaller than the target hole size for softwoods.
  • Use a bit exactly the same size as the hole when working on other materials.
  • If you’re not sure which to select, choose a drill bit 1/64” larger than the hole you wish to create. This will account for variables such a wood density and screw type.

Knowing how to choose the right drill bit takes practice, but don’t be intimidated. Carefully refer to your pilot hole charts before making your selection. Also, try to keep your drill bits organized in a storage case. This will make selecting the right size easier and more intuitive.

6 Comments

  1. Demario, January 26:

    Hello,
    Thanks for the good information. actually, I have a Question can you please suggest me what size drill bit perfect for Makita XT269M

  2. mike, January 31:

    The Makita XT269M looks like an excellent drill capable of handling wood, metal, and occasional concrete work. Which size you use depends on what you’re going to put into the hole. Which kind of drill bit you use depends on what material you’re drilling into. Cheap bits are OK, but get dull quickly. I suggest spending a little more to get sharp, hard bits.

    The most common sizes around the house are 1/16-inch, 1/8-inch and 3/16-inch. Get extras. You’ll also use some 1/4-inch bits.

    To install a common screw, measure the thinnest diameter–the shank– for a pilot hole in wood. For a through-hole, measure the outside diameter. For hard materials, add 1/64-inch.

    Black bits might be inexpensive and low quality for use on soft wood, or they might be the expensive hardened Bits with a golden color coating are harder. This is usually titanium or vanadium.

    Round shanks are cheaper, but can come loose in the drill.
    Hex shanks will stay in place better, but a cheap set will break too easily.

    At the tip, look at the angle. A flatter tip can skid across a smooth surface, so make a dent in the material first with a center punch and a mallet or hammer. A sharper angle will not skid as much, but I always pre-punch a guide hole to keep my bit on track when it starts up.

    Some tips have brads, very sharp needle points on the end. These cut wood very quickly, but can rip soft wood to ugly shreds. I only use brad tips where the result doesn’t need to be pretty.

    For metal, use the hardest bits at a slow speed, keeping the bit cool by squirting some cutting oil at the hole.

    For concrete, you MUST use bits with spades on each side of the tip. Non-concrete bits will take forever to get through concrete, if they manage to get through at all.

    Glass drilling needs special diamond bits.

    Spade (flat) bits make quick work of soft wood for bigger holes, like 1/2-inch to 1-inch, but the resulting hole might look rough.

    For neat, precise, larger holes, use Forstner bits. They are more expensive but worth it when you’re putting holes in the face side of nice furniture.

    Plastics are picky. They melt and deform. Secure the work so it can’t move, use a very tiny bit first to drill a preliminary guide hole. Then use the proper sized bit at the proper speed. Too fast will melt the plastic–too slow will grab the plastic and rip it–this takes practice.

    As soon as you feel a bit is perhaps a little dull throw it into your old metal recycling bin. Don’t waste time trying to drill things with dull bits.

  3. Ron Woltz, February 26:

    If you are using a helicoil for metrick what size do you drill in aluminum for a 3.5 diameter helicoil?

  4. helen, March 23:

    Hello,just want to ask about what proper size of drill bits do i need to use if i use #5 and #6 size of screws,please reply thank you

  5. Tina, June 22:

    If I use the drill bit diameter 5mm to dill in the solid wall, how the whole diameter of the solid wall it is?
    I want to make sure the tolerance of the hole?

  6. Keith, April 29:

    I have brought a 20mm masonry drill but it doesn’t seem to fit in my Black and Decker drill. The drill has 4 notches in the end that goes in to the three jaws of my B&D. When I tighten up the chuck the masonry drill moves all over the place. Please advise

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