What Size Drill Bit for a 3/4-10 Tap?

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¾- 10 taps are rarely used for people who have just started using drill bits themselves. They’re mainly used for making new threads or re-threading damaged threads. If you’re here to know what size drill bit for a ¾- 10 taps should be, read further.

What Size Drill Bit for a 3/4-10 Tap?

A ¾- 10 tap needs a size drill bit of 21/32 inches or 0.6562 in diameter. The ¾- 10 taps are classified as NC or national coarse. NC refers to Unified National Coarse or UNC. UNC has fewer threads and goes deeper than fine threads.

Don’t confuse this with the 3-48 tap with a drill bit of 5/64″ it is an entirely different tap. Although they are both NC, they have different sizing and should be used differently as such.

¾- 10 taps are generally used for cutting oil when cutting threads in metal, similar to the ⅝” tap with a drill bit of 17/32”. They can also be used for re-threading or making new threads for jammed or damaged threads.

Tips for Using Large Drill Bits

Make Use of the Hammer Action

Some drills have the hammer action feature. This allows you to “punch” on a hard surface repeatedly. For example, if you’re drilling through concrete, you might want to turn on the hammer action to make the drilling efficient.

Hammer action is a great feature, especially when using large drill bits for concrete. Concrete is hard to drill without the right equipment.

The hammer action makes a vibration that transfers to the drill bit that, gives it better penetration. This will lessen the time for you to drill on concrete and be less taxing on the drill bit since it’s supported by the hammering motion to penetrate the surface.

Keep A Spare Set of Drill Bits

You never know when your drill bit dulls or breaks. So having spare sets help replace them immediately. Another benefit of using two sets of drill bits is you can alternate them, so you have a sharp one at the ready.

Some professional drillers even use them at the same time. They use the new set of drills to drill a hole. The premise is that it keeps the sharper set for longer. After starting the hole, they switch to the old and sharpened set to finish the drilling making it less prone to dulling.

Monitor Your Progress When Drilling

As you are drilling, check your work to see if there are any adjustments you need to do. If there are lugs or jams, remove it and clean them up. You can use the bit to clear the hole from debris.

Make it a habit to pull out the drill bit every now and then and blow it off. This is important when you are drilling wood. Any flakes or chips of wood can get stuck in the bit.

The flakes and chips can make your drill bit heat up faster. This may be unnoticed by you. When your drill bit gets hot, it will function effectively less.


¾- 10 taps are rarely used, so it’s no wonder you’re looking for the right drill bit size. However, they are important for cutting oil when rethreading or making new threads. Make sure you follow the right drill bit size to get good results.