What Size Drill Bit for a 12-24 Tap?

As an Amazon Associate we earn from qualifying purchases.

12-24 taps are generally used for making new threads or re-thread damaged threads. If you’re here, you’re probably looking for what size drill bit for a 12-24 tap. It’s important to use the right drill bit size so the fit and function are correct.

What Size Drill Bit for a 12-24 Tap?

A 12-24 tap needs a size drill bit of 11/64 inches or a #16 drill bit. This equates to 0.1770 inches in decimals. The 12-24 tap is part of the NC thread just like the 4-40 tap. NC stands for National Course, also known as UNC (Unified National Coarse).

Man attaching a screw with a drill in an aluminum heatsink

UNC or NC is commonly used in the United States and Canada and is used as means to classify threads. Coarse threads are known for being deeper than fine threads like the 7/16-14 taps with a drill bit of 23/64″ and 3-48 tap with a drill bit of 5/64″ and with fewer threads per inch.

Tips for Using Medium Drill Bits

Measure Your Drilling Depth

When you are drilling, you often need to measure the exact depth as you don’t want to drill through or leave it shallow. Sometimes, you need to make a partial hole in a workpiece so measuring the exact depth is essential.

You can measure the depth you want to drill into by placing the drill bit next to the material. Mark the exact depth you want the drill bit to go and wrap a piece of tape around it as a guide.

The tape acts as a gauge as to when you should stop drilling. This makes the drilling easier since you can accurately gauge when to stop drilling for the right depth.

Wear Protective Eyewear

Since I’m dealing with medium drill bits, debris could fly away and land into your eyes. Accidents related to eyes are one of the most common mistakes people do when handling drills. It’s important to protect your eyes from flying debris, which might lead to serious injuries.

Wear safety glasses as a precaution. There is a lot of protective eyewear you can choose from that has different designs. Choose one that fits snugly in your head so it doesn’t wander off as you are drilling.

Drill, box of screws and other tools on a wooden table

You can put it in a checklist before drilling so you won’t forget to wear them. 

Deburr the Hole

Most medium drill bits are used for drilling holes. So, deburring the hole is a sensible thing to do. After you’re done drilling, make sure the hole does not have sharp edges or burr left in the hole. Feel the hole until it’s smooth.

It ensures your hole is smooth and clean, so you produce quality work. You can deburr a hole by running it in a bit of power and running the bit around the edges of the hole.

You can also use deburring tools to make the process simpler and easier. Most of them come with an instructional, so you should have no problems learning to properly use them.


The 12-24 tap is used for creating precise holes and is known for its versatility. Make sure you use the right drill bit size which is 11/64 inches so that it works properly and lasts long when being applied.