I am a frequent user of Tapcon bolts. In this guide, I will explain the correct drill bit size to use with 3 8 Tapcon. Always use the right size drill bit to avoid damaging your foundation.
Quick Summary: The drill bit size varies with the length and diameter of the given Tapcon. A 5/16-inch diameter drill bit is required for a 3 8 Tapcon screw. Always keep the length of the 3 8 Tapcon screws in mind. For instance, a drill bit with a length of 3.5″ is required for a 1.25″ Tapcon screw. A drill bit with a length of 4.5 inches is required for a 2.25-inch Tapcon screw.
A detailed description is given below.
Choosing to Drill it for 3/8 Tapcon
Before selecting a drill bit for Tapcon concrete screws, several considerations should be made.
- The Tapcon’s diameter
- Tapcon’s overall length
- The nature of the drill bit
- The application of the drill bit — the surface you want to drill
After determining these two dimensions, you can consult a respective chart to determine the appropriate Tapcon drill bit size.
Let’s go through each in detail.
The Tapcon’s Length and Diameter
The drill bit size varies with the length and diameter of the given Tapcon. The drill bit sizes are listed in the table below based on the diameter and length of the Tapcon (screw).
Based on the above data, a 5/16-inch diameter drill bit is required for a 3 8 Tapcon screw.
Always keep the length of the 3 8 Tapcon screws in mind. For instance, a drill bit with a length of 3.5″ is required for a 1.25″ Tapcon screw. A drill bit with a length of 4.5 inches is required for a 2.25-inch Tapcon screw.
Also, consider the length of the Tapcon screw when selecting a drill bit.
What Else to Know
Tapcon screws must adhere to the ANSI B212.15-1994 standards.
After setup, each Tapcon screw must meet the required embedment depth.
Minimum Embedment Depth
Every Tapcon has a minimum depth that it must penetrate the concrete.
If the screw does not meet this base value, it will not fit properly against the surface. This is referred to as the minimum embedment depth, and it varies depending on the diameter of the Tapcon screw. The table below will help you understand it better.
As shown in the table above, as the size (diameter) increases, so does the minimum embedment depth value.
Using a 3/8 Tapcon — Tips
Screw threads should be able to hold something. The holes you drill should be based on the screw shaft’s side.
The bolts need their threads, but they will be much larger. As a result, you should drill a hole larger than the outer threads. That being said, you’ll need to attach a 5/16″ bit to the drill.
Following that, drill a hole that is long enough and sufficient for the threads to support the bolt itself. After you’ve drilled the hole, you can insert the bolt.
It will be much easier if you have a drill that can also function as a torque wrench.
When to Use 3/8 Tapcon
It depends on the task for 3 8″ bolts. You can use it to secure table legs or other tasks that require a lot of reinforcement to keep things together.
Alternatively, depending on the material, you could use it to secure countertops in your bathroom, such as granite or sandstone. A torque wrench is required for securing bolts.
Bolts are your best bet when constructing a structure that can support a large amount of weight. When using a 3 8″ bolt, ensure it is securely fastened with no room for error.
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