HOME and how to join Forum Open Area General Scott topics special thread 5/8 x 20 tpi ?? Re: 20TPI screw threads


Further to my previous comments, please note that the 20tpi cycle thread is NOT of Whitworth thread form. Anyone thinking of screw cutting stuff on the lathe should cut threads with a 60 degree angle and not the 55 degrees of the various whitworth-based threads. For the record, BA threads are also not of Whitworth form. They have a 47.5 degree angle.