Planning for tapping with HAZ

Design
1

I have some holes in my parts that I want to tap. How do I plan for the hole size? Will the HAZ damage my taps?

2

If the holes in your parts meet our minimums, you could have us tap them for you! That said, if you have a thread pitch that we don’t offer or want to do them on your own here is how to plan for tapping parts we cut:

  • Scale your hole down 0.005" to 0.01" smaller than the drill size needed for that specific tap. This means that the hole in your part will be too small for the tap straight off the fiber laser.

  • Use the correct drill size and drill press to drill the hole to the correct size. The drill bit will remove any HAZ (heat affected zone) and ensure that you have a cylindrical hole for the tap. The HAZ on our parts is very small, but drill bits are more economical to replace than taps.

  • Tap the hole using a good quality cutting fluid, alignment block, and fixturing. Don’t force the tap, slow is fast in this instance.

Taps work best when they are cutting holes that are cylindrical. Drilling or reaming them to the best interior finish you can manage is going to be effort well spent as removing a broken tap is usually a nightmare. The more exacting you are about setup, use, and storage of your taps the more uses you will get out of them.

Happy building!