Drafting Question - How to specify that a thread boss should be fully threaded 1

[efulm4444]

Our components frequently feature threaded bosses with a groove at the far side for O-rings or as a thread tool relief. In these cases, we typically specify that the thread ring gage must contact a particular surface to ensure that the thread continues into the groove. There was a case where a vendor lifted the thread tool prematurely and it prevented proper assembly. Ever since, we felt the need to add this note.

Is there a way to specify this without pointing out a contact surface?

 

[greenimi]

You can specify the minimum full formed thread distance/ dimension added adjacent to the thread specification.
And if you feel that's not enough then on a separate note you can define what means "full formed thread"

 

[drawoh]

efulm4444,

I don't specify things like that. I prepare a drawing view that clearly shows what I want.

It looks to me like you need to choose between a nice radius that seals around your o-ring, or a thread that goes all the way to your bottom face.

--
JHG

 

[jassco]

Hi, efulm4444:

I agree with JHG's comment. Your statement is not clear. If the features are critical to your application, you need to add specifications.

You have two controls here. The first control is depth of threads. The second one is profile of the groove. You need to locate the groove since compression of the O-ring is important to you.

Best regards,

Alex

 

[CheckerHater]

I think the idea is to provide your vendor with something to measure - something that can be checked, either it's there or not.

https://files.engineering.com/getfi...5ba7acc38&file=2023-11-03_09-17-01_tpmwfb.jpg

"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future

 

[hydtools]

Add "full thread" to the thread callout.

Ted