# What Size Drill Bit Do You Need for a 34 Tap in Power Drills?

Written By John Gibbs
» Power Tools » Drill » Drill Bits » What Size Drill Bit Do You Need for a 34 Tap in Power Drills?

Are you wondering what size drill bit to use for a 34 tap? If so, you’ve come to the right place. This helpful guide will provide you with all the answers to the question: “What size drill bit for 34 tap?” Keep reading to find out the best drill bit size for a 34 tap.

## Drill Bit Sizes

### What Size Drill Bit for a 34 Tap?

The size of the drill bit to use for a 34 tap is a 7/16 inch bit.

### What Size Drill Bit for a 12 NC13 Tap?

The size of the drill bit to use for a 12 NC13 tap is a 5/16 inch bit.

### What Size Drill Bit for a 14×20 Tap?

The size of the drill bit to use for a 14×20 tap is a 9/32 inch bit.

### What Size Drill Bit for a 14 NC20 Tap?

The size of the drill bit to use for a 14 NC20 tap is a 7/32 inch bit.

## Steps for Selecting the Right Drill Bit

1. Determine the Threads Per Inch (TPI) of the Tap: To determine the size of the drill bit, you must first determine the Threads Per Inch (TPI) of the tap you are using. In this case, the tap is 14×20, so the TPI would be 20.

2. Convert Threads Per Inch to Drill Bit Size: Once you have the TPI, you must then convert it to a drill bit size. You can do this by using a chart that shows the conversion between TPI and drill bit size. For the 14×20 tap, the drill bit size would be 5/32”.

3. Select the Right Drill Bit: With the drill bit size determined, you can now select the right drill bit for the 14×20 tap. Make sure to select a drill bit that is slightly smaller than the drill bit size so that the tap can create threads in the hole. Once you have the correct drill bit, you can now drill the hole for your 14×20 tap.

4. Pre-drill the Hole: To ensure that the threads are cut into the hole properly, it is important to pre-drill the hole. This can be done using the drill bit that you selected. Make sure to drill the hole slowly and carefully to avoid any damage to the material and threads.

5. Tap the Hole: Now that the hole has been pre-drilled, you can now tap the hole using the 14×20 tap. Make sure to thread the tap slowly and carefully to avoid any damage to the threads.

6. Test the Threads: Finally, once the tap has been used, it is important to test the threads to ensure that they are the correct size and shape. This can be done with a thread gauge, which will allow you to measure the threads and ensure that they are the correct size and shape.

By following these steps, you can now answer the question “What Size Drill Bit for 14×20 Tap?”. Using the correct drill bit, pre-drilling the hole, and tapping the hole carefully, you can ensure that the threads are cut properly and securely.

## Factors to Consider when Choosing a Drill Bit

Size: When selecting a drill bit for a particular application, the size of the drill bit is the most important factor to consider. The size of the drill bit should match the size of the tap. For instance, a 1/4 inch drill bit is required for a 1/4 inch tap. Therefore, if you are looking for a drill bit for a 14 NC20 tap, you will need a 14 NC20 drill bit.

Material: Drill bits come in a variety of materials, each of which is better suited to certain tasks. Common materials used for drill bits include high-speed steel (HSS), cobalt, and titanium. High-speed steel is the most common material and is suitable for most general drilling applications. Cobalt drill bits are more durable and are ideal for drilling through hard materials, while titanium drill bits are best suited for drilling through softer materials.

Coating: Drill bits can also be coated with various materials, such as titanium nitride, titanium carbonitride, and tungsten carbide. Coating a drill bit can increase its strength and durability, and make it more suitable for certain applications. For instance, titanium nitride coating can help reduce friction and improve the drill bit’s resistance to wear.

Shank: The shank of the drill bit is the part that fits into the drill chuck. Drill bits come in a variety of shank types, including straight shank, quick-change shank, and hex shank. The quick-change shank is designed for use with a quick-change chuck, while the hex shank can be used with traditional drill chucks.

Flute: The flute of the drill bit is the part that cuts the material. Drill bits come in various flute types, including single flute, double flute, and spiral flute. Single flute drill bits are best suited for drilling through softer materials, while double flute and spiral flute drill bits are better suited for drilling through harder materials.

Point Angle: The angle of the drill bit point is also important when selecting a drill bit. Drill bits come in various point angles, such as 118 degrees, 135 degrees, and 140 degrees. The 118-degree point angle is suitable for most general drilling applications, while the 135-degree and 140-degree point angles are better suited for drilling through harder materials.

Overall Quality: Finally, it is important to consider the overall quality of the drill bit. The quality of a drill bit is determined by its construction, material, and coating. Higher quality drill bits are typically more durable and can withstand more wear and tear. Therefore, when selecting a drill bit for a particular application, it is important to choose a high-quality drill bit that is suitable for the task.

By considering the above factors, you can easily determine what size drill bit for 14 NC20 tap will be suitable for your application.

## Drill Bit Materials

When choosing the right drill bit for the job, it is important to consider the material of the bit. Different materials are better suited to different tasks. The most common materials used in drill bits are high-speed steel (HSS), cobalt, and carbide.

High-Speed Steel (HSS) is the most commonly used material for drill bits. It is strong and tough, and can be used on a variety of materials, including wood, plastic, and metal. It is a good choice for general-purpose drilling.

Cobalt is a versatile material that is heat-resistant and durable. It is best used for drilling through tougher materials, such as stainless steel and other metals.

Carbide is harder and more brittle than HSS or cobalt. It is usually used for drilling through extremely hard materials, such as hardened steel. It is also used for precision drilling.

## Drill Bit Geometry

When determining the correct drill bit size for a particular tap size, it is important to consider the geometry of the drill bit. The geometry of the drill bit determines the size of the hole that is created when drilling into a material. The most common drill bit geometries are:

Geometry Description
Twist Drill A twist drill is the most commonly used type of drill bit. It is designed to create a cylindrical hole in a workpiece.
Spot Drill A spot drill is used to create a “spot” or indentation in a workpiece for the purpose of drilling a hole.
Counterbore A counterbore is used to create a flat-bottomed hole in a workpiece.
Counter Sink A counter sink is used to create a conical-shaped hole in a workpiece.

It is important to select the correct drill bit geometry depending on the type of hole that needs to be created. For example, if a hole needs to be tapped, then a twist drill bit should be used. If a flat-bottomed hole is needed, then a counterbore should be used.

## Drill Bit Coating

Drill Bit Coating is a key factor for drill bit performance and durability. The type of coating on the drill bit can help make it more resistant to wear, corrosion and heat. Common drill bit coatings include black oxide, titanium nitride, titanium aluminum nitride and diamond.

• Black Oxide – This coating is popular for its affordability and provides a dark finish. It is often used in general purpose drilling.
• Titanium Nitride – This coating is very durable and provides a golden finish. It is popular for its ability to reduce friction and minimize heat build up.
• Titanium Aluminum Nitride – This coating is very corrosion resistant and provides a black/bronze finish. It is popular for its high lubricity and excellent wear resistance.
• Diamond – This coating is the most expensive and provides a bright finish. It is popular for its ability to drill through the toughest materials.

The right drill bit coating can help you get the job done quickly and efficiently. It is important to select the right coating for the job you are doing to ensure optimal performance and durability.

## Safety Precautions

Always wear safety glasses when drilling and tapping. Ensure that the drill bit is sharp, and use a slow speed to avoid overheating the bit. Use a lubricant like cutting oil when drilling and tapping. Keep all tools in good condition, and replace them when worn.

Always use the correct size tap and drill bit. It is important to use the correct size tap and drill bit to ensure the threads will fit correctly and to ensure the tap does not bind in the hole.

Never force a tap into a hole. If the hole is too small, use a slightly larger drill bit to open it up. If the hole is too large, use a slightly smaller drill bit to reduce its size.

Keep the tap straight while tapping. Use a tap guide if available. If the tap binds in the hole, back it out and try again.

Use a drill press instead of a hand drill for the best results. The drill press will keep the drill bit and tap in a straight line for even and accurate threads.

Secure the work piece with a clamp or vise. This will help prevent the work piece from moving while you are drilling and tapping.

## Frequently Asked Questions

### What is a Tap Drill Bit?

Tap drill bits are used for creating internal threads in pre-drilled holes. They are designed to cut threads into the material, which can then be used for fastening screws and bolts. Tap drill bits come in various sizes and shapes that are compatible with different thread types. The size of the tap drill bit is determined by the size of the thread being cut.

### How do I know which size drill bit to use with a 34 tap?

The size of the drill bit to be used with a 34 tap depends on the material being drilled and the tolerance required for the thread. Generally, the drill bit should be slightly larger than the outer diameter of the tap. Drill bit sizes for a 34 tap are typically 33/64 inch for aluminum and steel, 7/32 inch for brass, and 25/64 inch for stainless steel.

### Are there other factors to consider when choosing the right drill bit size?

Yes, there are other factors that should be taken into consideration when selecting the right drill bit size. The material being drilled and the type of drill bit should be taken into account. For example, masonry drill bits are best used when drilling into concrete and brick, while wood drill bits are best used for drilling into wood. Additionally, the type of hole being drilled should be taken into account when selecting the right drill bit size. For instance, a standard drill bit should be used for general-purpose drilling, while a step drill bit should be used for drilling larger holes.

### What is the Difference Between a Tap Drill Bit and a Regular Drill Bit?

Tap drill bits are specifically designed for drilling threads into a hole, while regular drill bits are designed for drilling general holes and for boring. Tap drill bits have a fluted or spiral shaped cutting edge that is designed to cut away material as it drills the hole. They also have a slight taper at the tip so that it can start the threads. Regular drill bits are designed to drill a straight hole, and do not cut threads.

### How can I make sure I am using the correct size drill bit for a 34 tap?

To ensure that you are using the correct size drill bit for a 34 tap, measure the shank diameter of the tap. Then, use a drill bit that is slightly smaller than this diameter. The drill bit size should be the same as the pitch of the thread. For example, a 34 tap with a 4mm pitch would require a 4mm drill bit. It is important to use the correct size drill bit to ensure the tap fits properly and does not become stuck.

## Conclusion

When looking for the right drill bit size for a 34 tap, consult a chart detailing drill bit sizes for each tap size to ensure accuracy. This guide has provided helpful information to assist in determining the right drill bit size for a 34 tap, allowing you to complete your project with ease and confidence.

## References

##### About John Gibbs

Hello everyone! My name is John Gibbs. I am 60 years old and have been in the family construction business all my adult life. Construction is not only my profession but also my passion. I know everything about building and repair materials, tools, advanced methods, techniques, and approaches. I will share the same knowledge with you in my articles.