6 Effective Ways to Remove Broken Taps
We’ve all been in this situation: You are working on a part with internal threads. The job seems fairly easy. You select the right tap, start working on the hole, and then suddenly, SNAP! and the tap is broken inside the hole.
Why did this happen? Not enough cutting fluid? Poor chip control? There are plenty of factors that can cause tap breakage, but at this point they are irrelevant. The broken tap is inside the hole and you only have two options: get it out or scrap the part.
Since scrapping the part should always be your last resort, you’ll have to figure out a way to get that piece of metal out of the cavity. But how? Here are several different methods to get the job done.
Manually smash the tap
This method is the most cost-effective, but also the least effective. You can break the piece using a cold chisel, in case part of broken tap is above the surface, and then complete the job using a center punch.
Most machinist have cold chisels and punches in their toolbox, but in case you are considering purchasing a new set, this 16-pieces set from Amazon is what we recommend.
Use an extractor
Extractors are devices specifically designed to remove broken taps.
They come in different sizes and with 2 to 4 “fingers” depending on the number of flutes. Using them is easy:
- Remove as many chips as possible from the hole
- Pick the correct extractor size
- Insert the fingers in the flutes as deep as possible
- Slide the collar down against the tap
- Use a tap wrench to turn it until the tap comes out
This method is fairly quick, but may not be very effective as the extractor fingers tend to twist off if the tap is too deep into the hole.
Mill the broken tap
One of the most effective ways to get rid of broken taps is to mill them out. Although there are several different endmills that you can use to get the job done, the majority of machinists who deal with this issue recommend using a ball endmill.
Grind it out with an Omegadrill
Omegadrills are uniquely shaped carbide drills, created specifically for removing broken taps. This method is very effective, but it requires a very rigid setup. You can purchase a set of Omegadrills on Ebay or through any premier distributor.
TIG welding is another practical way to remove the tap from the hole. The process, as clearly explained by Jodie Collier of WeldingTipsandTricks.com in the video below, consists of building up a head on top of the tap and then either grab it directly using vise grips or weld a nut on it.
EDM is probably the most reliable method to get the tap out of the hole. The EDM will burn out the center of the tap leaving just the cutting edges stuck in the threads, which you can then pick out by hand. Unfortunately, this is also the less practical method as most small shops don’t have access to electrical discharge machines.
Removing a tap from a hole is not impossible, but the process can be time consuming and not always successful. That’s why it’s important to take all the necessary precautions to avoid that situation. Using the right cutting fluid and making sure that the taps are in good condition are two fundamental steps to prevent tap breakage and keep the machines running.
Do you know any other effective methods for removing broke taps? Let us know in the comments below.