What is a 1/4 Tap Drill Size


A tap drill is a drill bit that is used to create an internal thread in a hole. The size of the drill bit is determined by the size of the tap that will be used for the threading process. The tap drill size is usually slightly smaller than the major diameter of the tap. The tap drill size must be chosen carefully to ensure proper threading.

What is the Size of a 1/4 Tap Drill

The tap drill size for a 1/4″ tap is #7.

Why is it Important to Know Your Tap Drill Sizes

Knowing the correct tap drill size is important to ensure that the threads of the tap match the threads of the hole that you are tapping into. If the tap drill size is off, the threads may not match up properly, which can lead to poor performance and even damage to your tools.


tap drill bit

How to Drill

Drilling with a tap drill is a fairly simple process. Once you have the right size drill bit, make sure your drill is set to the correct speed. Begin by drilling slowly with steady pressure into the material, making sure to keep the bit straight and level. If you are drilling into a hard material, you may need to use a lubricant to help the bit move through the material more easily. Once the hole is drilled, use the tap to thread the hole and complete the process.

Where Can You Use the 1/4 Tap Drill

The 1/4 Tap Drill size is most commonly used for tapping threads into a variety of materials such as metal [1], plastic, and wood. It is a versatile drill bit and can be used for a variety of projects, from creating a threaded hole in a machine part to installing a threaded fitting into a pipe.

What are the Other Tap Drill Sizes

The other tap drill sizes are:

  •  #4 (1/8″ tap)
  • #10 (3/16″ tap)
  • #14 (1/4″ tap)
  • #20 (5/16″ tap)
  • #27 (3/8″ tap)
  • #35 (7/16″ tap)
  • #41 (1/2″ tap)
  • #51 (9/16″ tap)
  • and #60 (5/8″ tap)

What Do I Need to Know Before Using 1/4 Tap Drill Size

Before using a 1/4 tap drill, you should make sure that you have the right-sized drill bit. Additionally, it is important to ensure that the surface you are drilling into is flat, clean, and free of obstructions. Finally, you should always wear the appropriate safety gear when drilling, such as safety glasses, hearing protection, and a dust mask.



A 1/4 Tap Drill size is a versatile drill bit that is commonly used for tapping threads into a variety of materials. It is important to know the correct tap drill size for the job and to use the correct safety equipment when drilling. With the right drill bit and a little bit of practice, you should be able to successfully thread a hole with the 1/4 Tap Drill size.

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