This tap needs to be wound all the way through both holes in the firebox sides in order to correctly align the threads. At 11 teeth per in, and about the same number of inches of thread, it isn't hard to see why it takes ages to do each one!
Today was spent inside and outside the firebox of 1638, reaming and tapping the stay holes, and then winding the new stays in. Needless to say, arms begin to ache after a while....
This tap needs to be wound all the way through both holes in the firebox sides in order to correctly
align the threads. At 11 teeth per in, and about the same number of inches of thread, it isn't hard
to see why it takes ages to do each one!