-
Welcome back Guest! Did you know you can mentor other members here at H-M? If not, please check out our Relaunch of Hobby Machinist Mentoring Program!
Drilling and tapping a hole
- Thread starter rdsii64
- Start date
- Joined
- Sep 28, 2013
- Messages
- 4,306
quicker and dirtier, hold the tap up to a light, hold a drill in front of the tap and see how much of the thread is visible. If all of it (both sides), try a thicker drill. If none of them, try a thinner drill. Ideally there'll be a Goldilocks drill where most of the thread is visible. Be careful though, go too small and/ or in hard/ gummy materials (or with small taps) and you run the risk of breaking a tap as you'll be trying to remove too much material.
Always back the tap out 1/2 a turn for every turn or so, clear out the threads every few turns, use tapping fluid (or WD40 for alu, dark sulphur oil for steel) and don't force anything. I've only ever broken one tap and it was because I didn't take my own advise. I was very annoyed with myself too!
**note, above advise may be useful if you're like me and only have a 29pc drill set!
Always back the tap out 1/2 a turn for every turn or so, clear out the threads every few turns, use tapping fluid (or WD40 for alu, dark sulphur oil for steel) and don't force anything. I've only ever broken one tap and it was because I didn't take my own advise. I was very annoyed with myself too!
**note, above advise may be useful if you're like me and only have a 29pc drill set!
- Joined
- Jan 3, 2013
- Messages
- 190
There are lots of good downloadable charts out there; look at the link below for some sources:
https://sites.google.com/site/lagadoacademy/useful-links#charts
https://sites.google.com/site/lagadoacademy/useful-links#charts
Last edited: