[imwllc]

hello, i got to quote a part for a customer and and i have to tap a hole in it that is called out as: G1/88 full thread, Minor dia. .3483 -.011, pitch dia. .3643 -.0042, major dia. .383 min, i did a google search and had zero results! i dont know if this is a government standard, i dont even know what kind of thread this is. if anyone knows anything, including where to get tooling if availible please let me know. thanks

[psychomill]

I think you're reading the print wrong or there is a slight typo (or maybe just hard to read).

The callout looks like a British pipe thread (dryseal type). This is a straight pipe thread, not a taper. The callout should be like this:

" G1/8B "

The last digit is a letter B, not an 8. That would make this thread a " 1/8-28, dryseal British pipe thread, external, class B ".

Look in a bible (Machinery's Handbook) and you can get all of the info.

Hopefully, they know what they are calling out, and not using the callout errantly. A male BSPP thread (British Standard Pipe, Parallel) will thread into a 1/8 NPT fitting (but won't seal). I've also seen many companies use this callout for American NPS threads (which is wrong - they're trying to be 'European', or shall we say 'metric').

:cheers: