wesright
Plastic
- Joined
- Jan 31, 2016
Hello, my question specifically deals with perception. I have a situation where someone broke a tap using it on a CNC mill. All other reasons and advice aside, this is dealing with what has polarized many people here. The tap used was a better quality 6-32 tap that has a thread length of roughly 0.440" and the 0.140" shank is turned down to 0.095" prior to the start of the thread.
For clarity and if anyone wants to look one up it was an OSG 6-32 split point tap and the MFG# is 1212400
Now, for most sizes these taps and many other brands in this style have held up very well. This time I am being pushed to stop getting these "weakened" taps and opt to get taps where the shaft has not been turned down: such as the Hertel taps that have a full 0.140" diameter shank all the way up to the threads and the thread length is longer, at around 0.850".
Sorry for the long rambling but all things being equal, is a tap like the OSG weaker and more likely to break when tapping using a CNC mill or I suppose even hand tapping?
I also do not like the idea that I have been told to, when possible, not get the "turned down" taps when a regular shank dia. tap is available. This seems wrong to me.
I fully realize that many, many more things are at play here. Material, hardness, hole type, speeds, feeds, etc. and the reasons for breakage can be complicated. I want to address the idea that a tap should not be chosen simply because of a singular feature (the turned down section) on the basis that it is weaker and will break faster than an identical tap with a full diameter in the same situation.
My question is simply this: Do I always choose a full shank diameter tap versus one that has been turned down because it is stronger and will not break as quickly?
I hope my rambling makes sense....Thank you for taking the time.
For clarity and if anyone wants to look one up it was an OSG 6-32 split point tap and the MFG# is 1212400
Now, for most sizes these taps and many other brands in this style have held up very well. This time I am being pushed to stop getting these "weakened" taps and opt to get taps where the shaft has not been turned down: such as the Hertel taps that have a full 0.140" diameter shank all the way up to the threads and the thread length is longer, at around 0.850".
Sorry for the long rambling but all things being equal, is a tap like the OSG weaker and more likely to break when tapping using a CNC mill or I suppose even hand tapping?
I also do not like the idea that I have been told to, when possible, not get the "turned down" taps when a regular shank dia. tap is available. This seems wrong to me.
I fully realize that many, many more things are at play here. Material, hardness, hole type, speeds, feeds, etc. and the reasons for breakage can be complicated. I want to address the idea that a tap should not be chosen simply because of a singular feature (the turned down section) on the basis that it is weaker and will break faster than an identical tap with a full diameter in the same situation.
My question is simply this: Do I always choose a full shank diameter tap versus one that has been turned down because it is stronger and will not break as quickly?
I hope my rambling makes sense....Thank you for taking the time.