|
Those have to be 5 mm. That would be 5 x .8. Your minor diameter is 4.2 mm and so is your drill size or .156 inch. Drilling very carefully on center of the broken bolt will take out everything but the threads. Leaving you to run a tap to clean out what is left in the threads. Just be careful about breaking a tap.
Minor is the diameter between threads, size - pitch = drill size. Pitches are equal in distance and depth of thread.
I live in a metric world
|