Through hull or skin fitting measurements

[Mark Thurlow]

I have been taught to measure the size of a male filling across the threads and a female fitting by internal diameter.

In the chandlers I picked up a marked 11/4” Male fitting but when I measured it it was 1 5/8’ and this difference was apparent on other fittings.

What am I missing here? I want to measure the skin fittings on the yacht and then buy them on line but how do I get the right size?

Mark

[deblen]

You have another step after measuring. You must look up the measurement in this table to convert to nominal pipe size. Hint: Pipe size is theoretically the I.D. of a length of pipe-not the fitting. / Len


https://www.plumbingsupply.com/pipethreadsizing.html

[deblen]

Proper thruhull instructions.


https://marinehowto.com/category/plumbing/