Threading fit issue, tapered?

[tobnpr]

Did you take any spring passes ?

I keep coming back to this. If there's minimal stickout/workpiece isn't deflecting, and the turned down tenon OD is consistent along its length, I don't see how it could be anything else.

 

[Ischgl99]

The thread mikes are sort of measuring a combination of both because if the thread pitch of the mike is slightly different from the cut thread it will not fit all the way to the bottom?

Thread mics measure on the pitch, not the bottom of the thread.

 

[GeneT45]

For the case you mention, thread micrometers or wires would be the first step in identifying the problem. You wouldn’t know if different measurements were cutting deeper in one spot, or if the pitch changes for some reason without further investigation. Thread micrometers are a direct reading version of wires, so there really isn’t much difference between them. The micrometers can be faster, and you don’t worry about dropping a wire in the chip pan, or wishing you had a third hand to hold everything while measuring.

Hopefully we all know to tie our thread wires together at one end with a rubber band, gob of chewing gum, play dough, or something else.

GsT

 

[Ischgl99]

Hopefully we all know to tie our thread wires together at one end with a rubber band, gob of chewing gum, play dough, or something else.

GsT

They're still a PITA to use.

 

[xr650rRider]

They're still a PITA to use.

Dab of Lucas red and tacky grease but thread mics are easier. If you learn to use and fit with thread mics, your part will fit across the world. Not just the one off XXXXX-not-so-precision thread out of a gun plumber shop.

Good reference for pitch measurement.
http://theoreticalmachinist.com/Threads_UnifiedImperial.aspx

 

[Ischgl99]

Dab of Lucas red and tacky grease but thread mics are easier. If you learn to use and fit with thread mics, your part will fit across the world. Not just the one off XXXXX-not-so-precision thread out of a gun plumber shop.

Good reference for pitch measurement.
http://theoreticalmachinist.com/Threads_UnifiedImperial.aspx

that’s how I do it, there’s always grease in the shop. I got a thread mic last spring for the 0-25mm range, nicer to use, but gets pricey to have the full range. I also have a go/no-go thread ring gage for a size I was making a bunch of parts for, when I win the lottery, I’ll have more of those lol.

 

[jareese]

Hopefully we all know to tie our thread wires together at one end with a rubber band, gob of chewing gum, play dough, or something else.

GsT

I've seen some use corks

 

[tobnpr]

Got all my thread mikes on Fleabay- all Starrett and B&S. Fraction of new cost. Can be tougher to find the standards tho...