# How to Find Drill Size From This Formula

Drill size is important for drilling into hard materials, such as concrete or rock. However, finding the right drill size is often a challenge. In this article, we will show you how to find the drill size using a simple formula.

A drill bit is one of the most important tools in a carpenter’s toolbox. It’s responsible for making precise holes in various materials, and without the proper size bit, even the most experienced carpenter can struggle. In this article, we will show you how to find the drill size from this formula:

Drill Size = 5/8″ + (Cutting Length ÷ 2)

This simple equation can help you find the right drill bit for any task. Let’s take a look at how it works.

## What is the formula to find drill size?

There is no set formula to find drill size, but there are a few methods that can be used. The first method is to use the inch measurement as the basis for calculation. For example, a 3/8 inch drill would be sized as a 3/8 inch drill. The second method is to use the metric system. For example, a 1.5 mm drill would be sized as a 1.5 mm drill. The third method is to use the standard drill bit size measurement. This would be the length in inches and the width in inches of the bit. For example, a 1/4 inch drill bit would be sized as a 1/4 inch drill bit.

There is no one definitive answer to this question, as the drill size will vary depending on a variety of factors including the material being drilled, the diameter of the bit being used, and the user’s experience and preferences. However, many drilling experts recommend using the following formula to calculate drill size:

Drill size (in inches) = bit diameter ÷ 6

There is no one definitive answer to this question. Drill size is typically determined by the type of drill bit that you are using and the material that you are drilling. In general, however, the formula used to find drill size is as follows:

Drill Size = bit width x Shank Length

## How to use the formula to find drill size?

Using the formula, drill size can be calculated easily. First, find the diameter of the hole you need to drill. Next, divide that diameter by the number of threads per inch (or whatever unit of measurement is being used). Finally, multiply that result by the number of revolutions per minute that the drill needs to make to achieve the desired depth.

If you have ever been in the market for a new drill, you have probably wondered what drill size to buy. That is why we are going to teach you how to use the formula to find drill size.

First, you will need to find the weight of the object that you are drilling. This information can be found on the product packaging or on the website where the product was purchased. Once you have this information, you can use the following formula to find the drill size:

Drill Size (in inches) = Weight (in pounds) x 0.79

If you’re looking to purchase a drill bit that is appropriate for your project, you can use this formula to calculate the size of the bit required:

drill bit size = hole diameter x 1.5

For example, if you need to drill a hole that is 3 inches in diameter, and the object you’re drilling is made out of metal, then your drill bit size would be 3 inches x 1.5, or 5.25 inches.

## What are the input parameters of the formula?

The formula used to find drill size is as follows:

drill size = (hole diameter) ÷ (reaming depth)

The input parameters are hole diameter and reaming depth. Hole diameter can be found by using a caliper or a measuring tape. Reaming depth can be found by using a reamer or a auger.

## How to output the results of the formula?

Assuming that you want to know the drill size (in inches) for a hole that is 3/8 inch in diameter, you would input the following into a calculator:

drill_size = 3.18

If you want to know the drill size for a hole that is 1/2 inch in diameter, you would input the following:

drill_size = 6.35

## Overview

Finding the right drill size is important for a variety of reasons. Not all drills are created equal, so it’s important to get one that will fit the job at hand. This guide will teach you how to find the right drill size using an easy formula.

To find the right drill size, start by measuring the diameter of the hole you need to drill. Next, divide that number by 2.14 to get the approximate number of mm (millimeters) that your drill bit should be. Finally, use that measurement to purchase a drill bit that corresponds to that size. You can also use this formula to figure out how many mm (millimeters) your current bit is larger or smaller than the ideal bit for your needs: 1 mm (millimeter) = 0.025 inches.

THREAD SIZE | DRILL (MM) | THREAD SIZE | DRILL (MM) | THREAD SIZE | DRILL (MM) |
---|---|---|---|---|---|

M1x0.25 | 0.75 | M9x0.75 | 8.3 | M18x2 | 16 |

M1.2×0.25 | 0.95 | M9x1 | 8 | M18x2.5 | 15.5 |

M1.4×0.3 | 1.1 | M9x1.25 | 7.8 | M20x1 | 19 |

M1.6×0.35 | 1.25 | M10x0.5 | 9.5 | M20x1.5 | 18.5 |

M1.8×0.35 | 1.45 | M10x0.75 | 9.3 | M20x2 | 18 |

M2x0.4 | 1.6 | M10x1 | 9 | M20x2.5 | 17.5 |

M2.2×0.45 | 1.75 | M10x1.25 | 8.8 | M22x1 | 21 |

M2.5×0.45 | 2.05 | M10x1.5 | 8.5 | M22x1.5 | 20.5 |

M2.6×0.45 | 2.15 | M11x1 | 10 | M22x2 | 20 |

M3x0.35 | 2.65 | M11x1.25 | 9.8 | M22x2.5 | 19.5 |

M3x0.5 | 2.5 | M11x1.5 | 9.5 | M24x1 | 23 |

M3.5×0.35 | 3.15 | M12x0.5 | 11.5 | M24x1.5 | 22.5 |

M3.5×0.6 | 2.9 | M12x0.75 | 11.3 | M24x2 | 22 |

M4x0.5 | 3.5 | M12x1 | 11 | M24x3 | 21 |

M4x0.7 | 3.3 | M12x1.25 | 10.3 | M25x1.5 | 23.5 |

M4.5×0.5 | 4 | M12x1.5 | 10.5 | M25x2 | 23 |

M4.5×0.75 | 3.75 | M12x1.75 | 10.3 | M27x3 | 24 |

M5x0.5 | 4.5 | M13x1 | 12 | M30x3.5 | 26.5 |

M5x0.75 | 4.25 | M14x1 | 13 | M33x3.5 | 29.5 |

M5x0.8 | 4.2 | M14x1.25 | 12.8 | M36x4 | 32 |

M6x0.5 | 5.5 | M14x1.5 | 12.5 | M39x4 | 35 |

M6x0.75 | 5.25 | M14x2 | 12 | M42x4.5 | 37.5 |

M6x1 | 5 | M15x1 | 14 | M45x4.5 | 40.5 |

M7x0.5 | 6.5 | M15x1.5 | 13.5 | M48x5 | 43 |

M7x0.75 | 6.25 | M16x1 | 15 | M52x5 | 47 |

M7x1 | 6 | M16x1.25 | 14.8 | M56x5.5 | 50.5 |

M8x0.5 | 7.5 | M16x1.5 | 14.5 | M60x5.5 | 54.5 |

M8x0.75 | 7.25 | M16x2 | 14 | M64x6 | 58 |

M8x1 | 7 | M18x1 | 17 | M68x6 | 62 |

M8x1.25 | 6.8 | M18x1.5 | 16.5 | M72x6 | 66 |

## UNC and UNF threads

UNC | DRILL (MM) | UNF | DRILL (MM) |
---|---|---|---|

1.64 | 1.55 | 0.8 | 1.25 |

2.56 | 1.8 | 1.72 | 1.55 |

3.48 | 2.1 | 2.64 | 1.85 |

4.4 | 2.3 | 3.56 | 2.1 |

5.4 | 2.6 | 4.48 | 2.4 |

6.32 | 2.8 | 5.44 | 2.7 |

8.32 | 3.4 | 6.4 | 2.9 |

10.24 | 3.9 | 8.36 | 3.5 |

12.24 | 4.5 | 10.32 | 4.1 |

1/4.20 | 5.1 | 12.28 | 4.6 |

5/16.18 | 6.6 | 1/4.28 | 5.5 |

3/8.16 | 8 | 5/16.24 | 6.9 |

7/16.14 | 9.4 | 3/8.24 | 8.5 |

1/2.13 | 10.8 | 7/16.20 | 9.9 |

9/16.12 | 12.2 | 1/2.20 | 11.5 |

5/8.11 | 13.6 | 9/16.18 | 12.9 |

3/4.10 | 16.5 | 5/8.18 | 14.5 |

7/8.9 | 19.5 | 3/4.16 | 17.5 |

1”8 | 22.2 | 7/8.14 | 20.5 |

1.1/8.7 | 25 | 1”12 | 23.2 |

1.1/4.7 | 28.2 | 1.1/8.12 | 26.5 |

1.3/8.6 | 30.8 | 1.1/4.12 | 29.5 |

1.1/2.6 | 34 | 1.3/8.12 | 32.8 |

1.3/4.5 | 39.5 | 1.1/2.12 | 36 |

2”4.1/2 | 45.3 |

## BSW and BSF threads

BSW | DRILL (MM) | BSF | DRILL (MM) |
---|---|---|---|

1/8.40 | 2.54 | 3/16.32 | 3.97 |

3/16.24 | 3.7 | 1/4.26 | 5.37 |

1/4.20 | 5.08 | 5/16.22 | 6.8 |

5/16.18 | 6.5 | 3/8.20 | 8.3 |

3/8.16 | 7.9 | 7/16.18 | 9.7 |

7/16.14 | 9.3 | 1/2.16 | 11.1 |

1/2.12 | 10.6 | 9/16.16 | 12.7 |

9/16.12 | 12.2 | 5/8.14 | 14.1 |

5/8.11 | 13.6 | 11/16.14 | 15.6 |

3/4.10 | 16.5 | 3/4.12 | 16.9 |

13/16.10 | 18.1 | 13/16.12 | 18.5 |

7/8.9 | 19.4 | 7/8.11 | 19.9 |

15/16.9 | 21 | 1″10 | 22.9 |

1”8 | 22.2 | 1.1/8.9 | 25.8 |

1.1/8.7 | 24.9 | 1.1/4.9 | 28.9 |

1.1/4.7 | 28.1 | 1.3/8.8 | 31.8 |

1.3/8.6 | 30.7 | 1.1/2.8 | 34.9 |

1.1/2.6 | 33.9 | 1.5/8.8 | 38.1 |

1.5/8.5 | 36.2 | 1.3/4.7 | 40.8 |

1.3/4.5 | 39.4 | 1.7/8.7 | 44 |

1.7/8.4.1/2 | 42 | 2”7 | 47.2 |

2”4.1/2 | 45.2 |

## BSP and BSPT pipe threads

BSP | DRILL (MM) | BSPT | DRILL (MM) |
---|---|---|---|

1/16.28 |
6.8 |
1/16.28 |
6.2 |

1/8.28 | 8.8 | 1/8.28 | 8.2 |

1/4.19 | 11.8 | 1/4.19 | 10.9 |

3/8.19 | 15.3 | 3/8.19 | 14.5 |

1/2.14 | 19.1 | 1/2.14 | 18 |

5/8.14 | 21.1 | 3/4.14 | 23 |

3/4.14 | 24.6 | 1”11 | 29 |

7/8.14 | 28.4 | 1.1/4”11 | 38 |

1”11 | 30.9 | 1.1/2”11 | 44 |

1.1/8.11 | 35.6 | 2”11 | 55 |

1.1/4.11 | 39.6 | 2.1/2”11 | 71 |

1.3/8.11 | 42 | 3”11 | 83 |

1.1/2.11 | 45.5 | ||

1.3/4.11 | 51.4 | ||

2”11 | 57.3 | ||

2.1/4”11 | 63.4 | ||

2.1/2”11 | 72.9 | ||

2.3/4”11 | 79.2 | ||

3”11 | 85.6 |

## Tapping drills for fluteless taps

METRIC | DRILL (MM) | UNC | DRILL (MM) | UNF | DRILL (MM) |
---|---|---|---|---|---|

1.6×0.35 | 1.45 | 1.64 | 1.67 | 0.8 | 1.38 |

2×0.4 | 1.8 | 2.56 | 1.98 | 1.72 | 1.69 |

2.5×0.45 | 2.3 | 3.48 | 2.27 | 2.64 | 2 |

3×0.5 | 2.8 | 4.4 | 2.56 | 3.56 | 2.31 |

3.5×0.6 | 3.2 | 5.4 | 2.89 | 4.48 | 2.6 |

4×0.7 | 3.7 | 6.32 | 3.14 | 5.44 | 2.91 |

4.5×0.75 | 4.2 | 8.32 | 3.8 | 6.4 | 3.22 |

5×0.8 | 4.6 | 10.24 | 4.34 | 8.36 | 3.84 |

6×1 | 5.6 | 12.24 | 5.01 | 10.32 | 4.47 |

8×1.25 | 7.4 | 1/4.20 | 5.77 | 1/4.28 | 5.94 |

10×1.5 | 9.3 | 5/16.18 | 7.3 | 5/16.24 | 7.5 |

12×1.75 | 11.2 | 3/8.16 | 8.8 | 3/8.24 | 9 |

14×2 | 13.1 | 7/16.14 | 10.3 | 7/16.20 | 10.5 |

16×2 | 15.1 | 1/2.13 | 11.8 | 1/2.20 | 12.1 |

## BA threads

THREAD | DRILL (MM) |
---|---|

5 | |

1 | 4.4 |

2 | 3.9 |

3 | 3.4 |

4 | 2.95 |

5 | 2.6 |

6 | 2.25 |

7 | 2 |

8 | 1.75 |

9 | 1.5 |

10 | 1.35 |

## How to use the formula

If you want to find the drill size from a given hole size, you can use the following formula:

drill size = hole size ÷ (1.5 – hole diameter)

A drill bit size is determined by the diameter of the bit and the drill’s speed. The formula for calculating drill bit size is as follows: (Diameter of Bit in Inches) x (Drill Speed in RPMs)

## What size drill bit should I buy?

There are a few ways to determine the size of drill bit that you need. One way is to use the formula:

d = 3.14 * r

where:

d – drill size in inches

\r – desired hole depth in inches (usually 1/2 or 3/4 inch)

If you want to know the approximate size of drill bit needed for a certain task, another approach is to use a drill guide. With a drill guide, you can insert the bit into the chuck of your drill, and then use the guide to measure the distance from one end of the bit to the other.

## What is a Drill Size?

If you’re looking to buy a drill bit, it can be a daunting task to figure out what size to get. Luckily, there is a simple formula that can help! The drill size formula is as follows:

diameter of the bit in inches multiplied by the number of teeth on the bit in points.Finding drill size from this formula can be a little tricky. If you are looking to purchase a drill bit, it is important to know the drill size that will fit the hole you need to drill. The formula below can help you figure out what size bit to buy.

Drill Size = 1/8th inch x Diameter of Hole x 12

For example, if you needed to drill a hole that was 3/4 inches wide and the object you were drilling was 3 inches in diameter, your Drill Size would be 12. This would result in a 1/4 inch drill bit being needed.

## How to Use the Drill Size Formula

When drilling holes in a project, it is important to use the correct drill size. The drill size formula can be used to determine the correct drill size for a given hole. This formula can be used with metric or English units.

The drill size formula is:

diameter = length x 0.6

For metric measurements, the diameter is rounded to the nearest tenth of a millimeter.

## What are the limitations of the drill size formula?

The drill size formula is a good starting point for figuring out the size of a drill bit, but there are some limitations to it. For instance, it only takes into account the width and depth of the hole, not the angle at which the bit is being inserted. Additionally, the bit size can vary depending on the type of material being drilled.

The drill size formula can be useful for estimating the size of a drilled hole, but there are some limitations to consider. The formula relies on the dimensions of the drill bit and the material being drilled. If the drill bit or material is different than expected, the resulting hole may not be accurate. Additionally, if the drilling depth is unknown, using the formula may result in an incorrect size.

## How to Calculate Drill Size from this Formula

In order to find drill size from this formula, you’ll need to know the nominal diameter of your bit, the number of threads per inch (TPI), and the size of your hole. To calculate the drill size, divide the nominal diameter of your bit by the TPI and then multiply that number by the size of your hole.Finding the drill size from this formula is an easy task if you have the correct pieces of information. The first step is to figure out the diameter of the hole you need to drill. The second step is to use the appropriate drill bit size based on that diameter.

## Conclusion

In this article, we will be looking at how to find drill size from a given hole using the formula P = Q * D. We will also explore some common problems that can arise when using this equation and how to solve them. So let’s get started!