I have two taps that are 4"-4 taps (that is, for four inch diameter bolts with four threads per inch). These taps are quite weighty, about
40 lbs each I would say. I realized that never in my life I ever saw 4" diameter bolts that could be screwed into holes tapped by those taps. Not even on the san francisco golden gate bridge, perhaps I missed something. So... has anyone ever seem such bolts or uses thereof? i- posted
17 years ago