Drill Bit Size Chart: A Complete List For Beginners – Cargister

Drill bits as we know, are the cutting tools that we use in drilling machines. Based on the purpose of use, the size and diameter of these bits can be of any value. But to deal with the difference in units and numbering methods, standard organizations have set up some certain size and diameter of drill bits.

You can just google with Drill Bits Size Chart and have any of the versions of this chart. But frankly, they are too hard to understand at first glance. You may need to start doing math with a calculator to understand which size of drill bit would do good for you.

But don’t worry. In this article, we’ll be making that chart easier for you to understand, and take you through all the various sizes of drill bits.

Which Drill Bit Sizes are Used in USA?

In America, the sizes of drill bits that are mostly used are- Fractional Inches and Gauge Drills. In other countries nearby, mostly metric size standards are convenient. Although, there are some other types of drill bit sizing manners-

  1. Number and letter gauge of drill bit sizes.
  2. Screw machine manner of drill bit lengths.
  3. Aircraft length drill.
  4. Jobber length drill.
  5. Center drill bit sizes.

However, we will be discussing fractional inches drill bit sizes here only, as this is supposed to be the most commonly used standard in USA.

Fractional Inches and Gauge Drill Bit Sizes

According to ANSI B94.11M-1979, this is the standard Fractional Inch drill bit size chart-

​Fractional Inches and Gauge Drill Bit Sizes

How to Pick up the Right Drill Bit Size for You

AS you have seen in the pilot hole chart, the diameter and letter indications can help you to get the right size of drill for your machine. The values are based on the shank of the screw and these guidelines will help you to pick up the right fit-

  • Don’t use a drill bit of exactly same diameter to your job hole. Use one that is approximately 1/64” smaller than the size of the hole (While working on woods).
  • Use the same size of drill bits to the job whole when you are working on other materials like metals etc.
  • If you want to create a new hole, chose a drill bit of 1/64” larger diameter than the hole you want to create.

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