Ok, so here's a weird problem. I am trying to make a 1/4 npt fitting with two pieces of brass pipe.(adsbygoogle = window.adsbygoogle || []).push({});

The tap says:

Vermont

1/4 NPT 18

HSGG M21

The die says:

1/4 NPT

Baystate -5

So I threaded the pieces of pipe, expecting them to fit together nicely... and they didn't - far from it. I found that they were screwing in at an angle, and stopping after a short distance.

Needless to say I'm mystified by this. I've tried threading several pieces, being careful to make nice straight threads, and still this problem remains. I suspect it must have something to do with that "-5" on the die, but I haven't been able to find any references explaining what it means.

Please help!

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# Help! Npt sizes not fitting!

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