In this article, ill teach you what size drill bit you should use for 1/4 Tapcon.
If you drill a larger hole for a Tapcon concrete screw, there won’t be enough material to hold the threads of the screw. On the other hand, a smaller hole won’t do any good for you. So, using the correct size drill bit for ¼ Tapcon is much more important than one might think.
In general, the drill bit size depends on the diameter and the length of the Tapcon screw. For ¼ Tapcon, you’ll need a 3/16-inch diameter drill bit. And the 3/16 Tapcon screw needs a 5/32-inch diameter drill bit.
What Are the Factors that Change the Tapcon Drill Bit Size?

Before choosing a drill bit for Tapcon concrete screws, you should pay attention to two things.
- The diameter of the Tapcon
- The length of the Tapcon
After correctly finding these two dimensions, you can use a corresponding chart to figure out the correct Tapcon drill bit size.
What Size Drill Bit for 1/4 Tapcon

As mentioned in the above section, the size of the drill bit changes according to the length and the diameter of the Tapcon. The following table shows the drill bit sizes according to the diameter and the length of the Tapcon screws.
Note: The below results are for the Straight Shank Carbide Bits.
Tapcon Screw | Drill Bit | ||
Diameter | Length | Diameter | Length |
3/16” | 1.25” | 5/32” | 3.5” |
3/16” | 1.75” | 5/32” | 3.5” |
3/16” | 2.25” | 5/32” | 4.5” |
3/16” | 2.75” | 5/32” | 4.5” |
3/16” | 3.25” | 5/32” | 4.5” |
3/16” | 3.75” | 5/32” | 5.5” |
3/16” | 4” | 5/32” | 5.5” |
¼” | 1.25” | 3/16” | 3.5” |
¼” | 1.75” | 3/16” | 3.5” |
¼” | 2.25” | 3/16” | 4.5” |
¼” | 2.75” | 3/16” | 4.5” |
¼” | 3.25” | 3/16” | 4.5” |
¼” | 3.75” | 3/16” | 5.5” |
¼” | 4” | 3/16” | 5.5” |
¼” | 5” | 3/16” | 6.5” |
¼” | 6” | 3/16” | 7.5” |
According to the above data, for a ¼ Tapcon screw, you need a 3/16-inch diameter drill bit.
However, pay attention to the length of the ¼ Tapcon screw. For a 1.25-inch Tapcon screw, you’ll need a drill bit with a 3.5-inch length. And for a 2.25-inch Tapcon screw, you’ll need a drill bit with a 4.5-inch length.
So, always consider the length of the Tapcon screw before choosing the drill bit.
If you use a 3/16 Tapcon concrete screw, you’ll need a drill bit with a diameter of 5/32 inches.

Don’t Forget: A ¼ Tapcon screw, ¼ refers to 0.25 inch.
Apart from that, here are a few things you should know about Tapcon screws.
- All Tapcon screws should follow the ANSI B212.15-1994 standards.
- Each Tapcon screw should meet the minimum embedment depth after installation.
What is Minimum Embedment Depth?

Each Tapcon screw has a minimum depth that it should reach on the concrete surface. (1, 2)
If the screw doesn’t reach this minimum value, it won’t fit correctly with the surface. This value is known as minimum embedment depth, and it varies according to the diameter of the Tapcon screw. You’ll get a better idea about it from the following table.
Diameter of the Tapcon | Minimum Embedment Depth |
3/16” | 1” |
¼” | 1” |
3/8” | 1.5” |
½” | 2” |
5/8” | 2.75” |
¾” | 3.25” |
As you can see from the above table, when the diameter increases, the minimum embedment depth value increases accordingly.
Quick Tip: An ¼ Tapcon should reach 1 inch of minimum embedment depth.
Take a look at some of our related articles below.
References
(1) minimum depth – https://www.geeksforgeeks.org/find-minimum-depth-of-a-binary-tree/
(2) concrete – https://www.homedepot.com/c/ab/types-of-concrete-mix-for-any-project/9ba683603be9fa5395fab901c07575fe
Video References
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