Taps are made from very hard but very brittle material. This means, that even under a small stress your tap will break in two, especially those smaller sizes. We all know what a pain in the butt is to extract a broken tap from our workpiece, so we better do anything we can to prevent this from happening.
Step 1: Lubrication
When cutting threads always make sure to use plenty of cutting fluid. Some high end cutting oils can be expensive, but there is no need to go that way. Regular sunflower oil is more than good enough and you can get a lot of it for no more than several bucks.
Step 2: Breaking the Chip
Second thing to prevent you from running to your tap dealer every hour is also very simple, but apparently rather unpopular.
A lot of people just turn their taps in all the way. This may work, especially for thinner materials. But what happens is that when you´re creating the threads, you are cutting in the material and therefore crating chips. If you are cutting using just one nonstop motion, you are creating one long chip. This long string of metal has virtually no way to evacuate from the flutes of the tap and that´s when you break it.
To prevent this from happening, only thing you need to do is to cut the thread intermittently. Don´t get me wrong, you don´t have to take a half hour brake after every turn. What I had in mind is that after every 360° turn you go half turn (180°) back, Doing this, you are breaking the chip and instead of one continuos clingy chip, you get lots of small chips, that can be easily flushed away with cutting fluid or air.
Thanks for reading, make sure to let me know what do you think of this technique, or if you have any tips for thread cutting. Please subscribe to my YouTube channel, I post new #QuickTip like this on mondays and new project video on thursdays and don´t forget: get inspired, use what you have and make the best out of it!