Given the ever-improving quality of taps, modern tap designs can be expected to last between 15 and 20 years typically.
My seven ways to avoid breaking a tap include:
1
Choosing the best hole size.
2
Using form taps when possible.
3
Thread mill critical and tough jobs.
4
Use purpose-made tapping lubricants.
5
Use the right tool holder.
6
Extract chips with a spiral-fluted tap.
7
Mind the depth on blind holes.