manually measured thread.. stupid question. 2

[TheMotionGuy]

I've been asked to have some parts re-made.. But the old drawings have been lost in the abyss. So, I had to get out my thread gauge and micrometer/caliper.

The question is: If i measure a male thread at 1-5/8"-12, and the female at 1-1/2"-12. What am I going to call out for the respective threads in the drawing?

Do I call out 1-1/2"-12 or the 1-5/8"-12? I'm not sure which correlates to the tap/die sizes.

Sorry this is kind of a stupid question... but hey..

 

[CoryPad]

Your dimensions are major diameter for external thread and minor diameter for internal thread? Then use the external thread major diameter, that is the basis for the pair.

 

[TheMotionGuy]

Yes, major and minor diameter for external and internal threads respectively. Thanks, I'll use the external thread major diameter.

 

[hydtools]

1-5/8-12 UN 2A for the male
1-5/8-12 UN 2B for the female

The ID of the female thread is ~1-1/2"

Ted

 

[KENAT]

Why did you even bother inspecting the female thread if you know the parts mate and they aren't so critical that verification of class is likely to be required?

Just measure the easier to access male.

Posting guidelines faq731-376

http://eng-tips.com/market.cfm?

(probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​

 

[telecomguy]

Ummm, suppose the female thread was the easier to inspect. Then the OP would have been trying to spec a 1-1/2" thread...

 

[TheMotionGuy]

Well, I had only female threads available. The other piece was in use in our manufacturing dept. There was a production run going, so i had to wait for it to be taken apart and cleaned before I could get to it.

Also, like I said in my original post, I didn't know whether I needed to call out the male or female diameter.

But thank you all.