What Size Drill Bit for a 1/2” NPT Tap?

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The ½” NPT tap is a common tap mainly used to cut pipes’ internal threads. ½” NPT taps are generally made of steel and are usually heavier than most taps If you want to know what size drill bit for a ½” NPT tap is, read further.

What Size Drill Bit for a 1/2” NPT Tap?

A ½” NPT Tap needs a size drill bit of 23/32 inches or 0.7188 inches in decimals. NPT taps are also called pipe taps, and don’t confuse them with NPTF taps and tapered taps like the ⅞- 9 tap.

Workman screwing window frame during housework

NPT taps can be carbon steel, HSS, or Interrupted thread NPT taps. Carbon steel NPT taps are generally used for cleaning or re-threading damaged or jammed pipe threads like the 3-4 NPT tap. High-speed NPT pipes are for making new threads and for re-threading also.

If you plan to use NPT threads, do know they require a sealer like Teflon tape or pipe compound.

Tips for Using Large Drill Bits

Avoid Jamming Your Drill

One common thing when using large drill bits is jamming. It’s a common mistake amateur drillers make since they usually apply more pressure when drilling, which leads to jamming. You should learn how to avoid jamming your drill.

When you jam your drill, you might have to replace the tip, and your drill’s lifespan will shorten. You want to avoid spending more than you should when it’s avoidable. One thing you can do is not apply too much pressure when drilling.

Also, feel the drill and spot when you think it is slowing down. Pull it out when you think it’s slowing down and let it cool for a while, cleaning off any debris stuck in the drill.

Don’t Use Excessive Force

Large drill bits naturally make people think that you have to use more power. However, that is not the case. It’s better to focus on precision instead of power. When drilling, you must hold the drill vertically at all times for consistency.

Drill bits, screws, protractor, and measuring tape placed on top of a table

You want to hold a 90-degree angle while you let the bit drill for you. A slight bend could cause the hole to be unaligned, and the exit hole will not be where you want it to be.

It’s wise to not use excessive force that can affect your accuracy and stability when holding the drill.

Avoid Wearing Loose Clothing

One thing that you must absolutely avoid is wearing baggy or loose clothing when drilling. Remember, you are using large drill bits, so the chance of your clothing getting tangled with the drill is higher than using a small drill bit.

You want to avoid wearing anything loose or anything that can potentially entangle with the drill that will cause an accident. This also applies to your hair if you have a long one. Make sure it’s tied up and kept neatly, or use a hair net.

Wear tight clothing or better protective clothing for drilling. Also, avoid wearing jewelry while drilling.


½” NPT taps need a large drill bit size of 23/32 inches and can be used for a wide range of materials. They’re mostly used for cleaning and re-threading. If you’re gonna use them, make sure to have a sealer for the threads.