Still more- if you grind the tip, I would expect that it would anneal the steel, causing is to wear quicker.
Also- Taps break because
(a) they are brittle- and cheap ones are MORE brittle,
(b) because the pilot hole is incorrect - too small, often when we don't have the standard pilot size which is most often a number or letter drill, OR you use a fractional (like 3/64 - "That's close") drill you have as a pilot for a metric tap.
(c) because they are inserted incorrectly into the pilot hole (crooked), and more often
(d) because "chips" load up in the area allowed for this debris. Once the chips FILL the relieved area, then the tap binds, and can break.
SO- "woodpeckering"- this technique needs to be used in tapping.
Turn the tap in 1 turn, then backward 1/3 turn to relieve the chip, with oil to lubricate. Repeat.
