[jsclark]

I'm using a threadmill on a cnc machine and trying to make a 1 3/16"-16 internal thread at H11 Tolerance. Do I just make the major diameter larger? this is something that is new and confusing to me. I have read up on H tolerances but I guess not good enough.. If anyone can relate to this or can explain how to do this that would be great.

Thanks

[arikaa]

You should make it 0.016 smaller. What kind of matirial you are using?

[arikaa]

0.016 smaller.

[arikaa]

Sorry. 0.016 mm smaller.

[jsclark]

Thanks for the reply, I'm using 6061 and 7075 Aluminum

[jsclark]

Wouldn't I make the threads larger because its an internal thread?

[Superman]

For a Ø1.1875" ( Ø30.163mm ) with H11 tolerance

H11 tolerance on Ø30 to 50mm range is +160μm to 0μm....... Hole basis chart link
0.160mm = 0.0063"

so then your nominal pitch diameter is Pd=D-(0.6495/TPI)....=...1.1875-(0.6495/16)....=....1.1469....this is your lower limit
upper limit is 1.1469+0.0063 = 1.1532"

If you wanted to do it correctly, you may wish to make GO-NOGO gauges,
--- turn 2 external threads to the correct pitch diameter....your GO must screw in to full depth,,,.the NO-GO can start by 1-2 turns, but not be able to screw in at all

I would program to nominal size, and adjust the tool offset in the machine to get finish size.....make the tool smaller to cut the thread larger