If their standard electrical compression fittings that are made to take the standards flat nut that mount them in the side of an electrical box, they are straight pipe thread. They're the same thread per inch as tapered pipe thread, but there's no taper to them. You may be able to run a die over the thread and put a little taper on the nose of then and get them to work, but if you don't have enough taper, their not going to seal properly.
Actually what your using isn't really water tight for use under pressure. You may get lucky and have it work but it may weep also.
Something to look out for is, if one end of the cable is opened to water, that water will find a path right through your cable. It will actually seep through the cable between the strands of wire and through the filler strings in the cable. If both ends are sealed in pods water through the cable isn't a problem unless you have a flooded pod but you'll probably be on the surface before seeing a drop of water in the hull even if that happens.
Dan H
Robert Carlson wrote:
I'm using a standard compression fitting for cable thru hull connectors but I'm having the darndest time trying to match the threads with a tap. I assumed they were NPT (i.e. pipe thread) but was told that they have their own thread type. Can anyone help me on a source for taps to thread a hole for these threads?
Rob Carlson