I have a flange that I have designed to mate with a 4" male NPT (tapered). I have never had to designate anything other than standard threads before, so I am at a loss here. I had a simple callout notating " 4" NPT TAPERED " - my co-engineer marked it and said that I needed to indicate thread engagement as well.

Based on this website: Normal Engagement Length of NPT Thread in Inches (A) - Technical Reference - Technical Literature - JGB Technical Inform…

My engagement should be 1-1/8". However, when I look at previous models with similar design (same size NPT), they are seated at 7/8" - as well, my design has the unit seated at 7/8" as well.

I know that this is really more of an engineering question vs. a Solidworks question, but I feel pretty sure that some of you are engineers (like myself) and can help answer this question.

Then, just to keep it Solidworks related...how would you notate that on a drawing?