On 21/04/17 13:35, wrote:
On Fri, 21 Apr 2017 10:21:56 +0700, John B Slocomb
wrote:


And it depends what you are threading the bolt into. Using fine
threads in coarse grained cast iron is generally NOT a good idea.

As far as the actual "thread area" there is very little difference. If
you double the TPI the threads are only half as deep, but there are
twice as many threads so the total load bearing area is not much
different.


Thread area isn't the issue that John brought up.

--
JS