6-32 Tap Drill Size

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A tap is required to make threads of screws to adjust for different materials and degrees of symmetry. However, you first need to know the correct drill size for the tap, as every tap has a corresponding drill size, which is crucial for drilling. 

Our engineers will detail the 6-32 Tap Drill Size and know-hows. Let’s start! 

Drill Bit Size for a 6-32 Tap

One of the most commonly used taps is the 6-32. It is ideal for cutting brand new threads or cleaning out damaged ones in a formerly tapped hole. This kind of tap has different taper threads at the end to guide it within the hole.

6/32 tap drill bit size

The correct drill bit size for a 6-32 tap is No.36, with a decimal equivalent of 0.1065. You’ll need to take note of the correct drill bit size to get the best outcome. 

How to Find Out the Drill Bit Size for a 6-32 Tap

6-32 Sizing

A 6-32 Thread Tap sizing includes close and free fit sizes. The close fit size for a 6-32 tap is 27, with a decimal equivalent of 0.1440.

On the other hand, for the free fit size, it should be 25, with a decimal equivalent of 0.1495. Note that this sizing applies to aluminum, copper, bakelite, cast iron, or any thin materials. Also, our engineers suggest that you can use one drill size larger. 

Calculating the Size of the Tap Drill

1. You’ll need to measure the overall diameter of the tap you want to use. 

2. Then, use this formula– Dh = Dbm — 0.0130 (your desired entire thread percentage/ Ni). Note the following terms:

6/32 tapping

3. Apply the figures based on the formula with a thread of  84 percent (for example). 

4. Then, find the closest tap drill bit size using 1/16ths of an inch. Multiply the figures from the formula by 16. 

drilling with 6/32 tap

Note: If the drill bit size you get is too undersized, we suggest determining the correct size of the drill bit in 32nds per inch. So, instead of multiplying the figure by 16, you will multiply it by 32. 

Why Do 6" and 32" Tappings Require Different Sizes?

The 6″ and 32″ tappings require different sizes because of the close fit and free fit clearance hole, which applies to all materials.

As we mentioned earlier, the close fit drill size for a 6-32 tap is 27, while the free fit drill size is 25. The clearance allows the tap to adjust and fit in the drill perfectly. 

How to Drill With 6-32 Taps

1. To drill with 6-32 taps, you need to determine the diameter of the drill you will use. 

6/32 tap

2. Secure the blade and the clamp and hold the drill with the clockwise rotation. You can add a bit of oil to the thread for smoother drilling. 

3. Then, point the thread tap on the surface you want to drill and slowly go through the material to make a hole. We suggest not using the clutch all the time. If you need to stop the drill, do it, then go one again. 

4. Move the drill forward and backward until you entirely make the holes. 


What is the diameter of a 6-32 tap?

The diameter of a 6-32 tap is 0.1380 inches with a tap drill size of No. 36. Here is a tap drill sizing chart online that you can refer to if you’re unsure about the sizes and measurements.  


Taps are commonly used to cut threads for screws [1] and bolts into plastic, wood, or metal. So, a hole for a specific size is required for the tap. Also, an improper drill bit size would not let the tap fit in the hole. 

And as we detailed above, the 6-32 tap drill size must be No. 36. You can use it for iron, stainless steel, aluminum, brass, copper, plastic, bronze, and nickel-based materials.

Robert Johnson is a woodworker who takes joy in sharing his passion for creating to the rest of the world. His brainchild, Sawinery, allowed him to do so as well as connect with other craftsmen. He has since built an enviable workshop for himself and an equally impressive online accomplishment: an extensive resource site serving old timers and novices alike.
Robert Johnson
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