How to Determine Drill Bit Size for Screw: 5 Easy Step

Before you start your foundational building block, you should determine the drill bit size. Although some people think it is the most unimportant task, it’s not at all. Determining your drill bit size is the fundamental task that will allow you to reshape everything for completing your entire project.

But, the problem happens when you don’t know exactly how to determine drill bit size for screw? Well, here you’ll get a well-researched step-by-step guide that will assist you to begin your process. After reading this article, you will be able to find out the right size like a pro. And, your screws will go easily once you can recognize the right drill bit size.

Also, we will assist you to know how many drill bits you require for your project, how to get a perfect pilot hole, and all the safety measurements. So, let’s begin!

Number of Drill Bits You Need for Your Project

For most of the drilling cases, you need not too many drill bits as you don’t need to get lots of precision.   If your project is about the basic DIY works for your house purpose, you need not more than 230 pieces of bit set.

So here, you can easily determine the drill bit size and start working on your next project. Besides, these 230 pieces of drill bits will be well enough to cover any of your big DIY projects.

5 Steps on How to Determine Drill Bit Size for Screw

How to pick the right drill bit for a screw

Here are five essential steps that will help you find out the correct drill bit size for your screws. All you should do is follow these steps the way we suggested below-


Check out the diameter of the screw and try to match the drill, but, not with that screw root. To compare the screw diameter closely, hold the drill bit right next to the screw.


To drill the hole, you have to place your drill bit aside from the material. A small size drill bit compared to a screw root will be perfect while working with softwood material.


Once you complete step 2, you will require one more drill bit for placing it against the screw shank. Remember, while working with sheet metal screws, you will not get any shank available there. So, you have to go simply for a pilot hole.

But, if the shank is available there in the screw, you will have to choose the same size of drill bit considering the screw shank. The drill bit size will be the same as the shank while it is hardwood, but smaller while it is softwood.


As long as you need to get a bunghole, determine the screw head diameter in the first phase. Later, you have to cover up the screw head with a plug right under the surface. Here, you have to choose your drill bit a bit larger or the same size considering the screw diameter.

Again, you’ve to focus on the screw style, for instance, if you’ve got a flat-head style screw, you must choose a cone-shaped countersink drill bit. And, it should be a bit large so that you can easily sink the screw head.

Step 5

To determine the depth of your required hole, we recommend you measure the screw shank length along with the whole screw length. Adjust the thickness of your screw head if it is a flat-head screw. And, these measurements will determine the depth of the shank hole and a pilot hole at the end.

How to Make Pilot Holes Perfectly?

It’s now time to know how you can drill a perfect pilot hole for your screw right after recognizing the correct drill bit size. If you can make the pilot hole accurately, it will allow you to place the screw in the right place. 

And, if you cannot make an accurate pilot hole, you will have to face lots of problems like splintering, bit breaking, wood chips, etc. But, nothing to be worried about as this part of our article will guide you to make an accurate pilot hole. Let’s know, how:

  1. Take a marker or pencil and determine the space where to screw so that you can start the hole from the exact spot. It is such an easy step that will save your time, lessen your worry, and give you an accurate outcome.
  1. Use clamps while working through wood or hard metal. But drilling through a stable surface or wall will not require any clamp to seal down.
  1. Since you require a hole that stays straight up and down, you have to go through strong grief. Therefore, make sure you’ve placed the drill bit vertically and lined it upright with the marked spot. If you miss maintaining this step, it will cause your hole to be sideways or slanted.
  1. Drilling directly through the surface necessitates you to stop once when the drill comes out of the other side. Also, you have to ensure the drill bit isn’t getting out of the marked dimension. Because if you drill far from the spotted dimension, you will not gain a perfect pilot hole.
  1. Pull out your drill bit in slow motion while spinning and keep doing the same thing several times until you are done. It will help you prevent the wood debris to get a good polish.
  1. You are now ready to use the screw to make your pilot hole. But remember to wipe away all the debris properly because if you don’t remove the debris it will be stuck to your screw. So, to make an accurate hole, you must prevent the dust carefully.

Safety Issues

Even though determining the right size of your drill bit for screw and to drill a pilot hole isn’t that risky, it’s still very significant to maintain some safety issues. Because using a power tool is always required to be safe to lessen unexpected risks. Let us help you know what to do and what’s not while working using a drill bit.

Wear a full sleeve shirt to keep your skin safe, and also, you need to wear goggles on your eyes and gloves on your hands. All these mentioned gears will help you be safe during your drilling time.

Besides, we strongly recommend you avoid the soggy logs. It’s quite risky to work through watery logs. And, don’t purchase any cheap drill bit and screw. Another important factor to consider is to avoid recklessness in your work. Go steady and slow to get a good and safe finish.

To Wrap Up

Your drill bit should be the same/correct size considering your screws. Because the drill bit doesn’t come in the right size, you will fail your projects. But, choosing the right size for the drill bit and screws will make a massive difference.

However, following what is told in the second section of our article would help you know how to determine drill bit size for screw? And, you can now easily determine the correct size to complete your job.

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Sam Morgan is a professional interior designer and part-time content writer of Drill Villa. He has done hundreds of major projects and sharing his experience with you. He is a tools lover like drill, drill press, drivers, wrench etc. He used and tested thousands of tools and knows which perform better.

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