Gagemaker thread pitch diameter location template question

[Quality Josh]

Was just wondering if anyone knows if the distance to the notch on gagemakers pitch diameter location templates is a standard distance from the shoulder given in API spec 7-2 or if it is a special distance and diameter that Gagemaker has calculated? The reason i ask is because i have been asked to verify this distance and i'm not sure the value it is suppose to be.

 

[The real Leigh]

...i have been asked to verify this distance and i'm not sure the value it is suppose to be.

The most accurate response to that query results when you do NOT know what the answer should be.

- Leigh

 

[specfab]

Maybe this helps to answer your question:

How To Use API 7-2 Thread Gauges

Looks to me like there is a standardized gage standoff distance, at least as it relates to Northern Gage stuff. I assume that this is based on a standardized shoulder distance for gaging as established in API 7-2. If you have the 7-2 spec, that's the place to confirm.

 

[4GSR]

Damn auditors....

Probably need to edit your quality documents to dictate this as being a given provided by Gagemaker. And that Gagemaker is God and no future explanation is needed.

 

[Heavey Metal]

= gage standoff.

Be careful cause you may need to calibrate your sharpie.

Notch for taper would be calculated.

 

[Quality Josh]

I am glad these are the answers im getting, makes me feel like way less of an idiot. So stand off is suppose to be 0.625" but it is nowhere near that from the end of either the box template or the pin template. Im going with it must be a calculated value. They dont make life easy do they!

 

[4GSR]

The calculated value is based off of the pitch diameter at the .625" standoff from the face or shoulder of the connection.

Gagemaker takes a sample of the thread that is somewhere between the .625" length dimension and somewhere down the taper of the thread, based on the thread rolls used for the measurement. And their magic number they use for standoff is only used with the PD instrument, to set the instrument as well as used for checking the correct PD of the tool joint thread. This calculated dimension takes in account the taper of the thread and how far it is from the .625" standoff dimension to create the new PD dimension. But you also have to take in consideration, GM has built in factors they don't tell you about that are part of the calculations they have created. They won't tell you these factors either! Now explain this factor thing to your auditor...

 

[Quality Josh]

It is a very annoying situation especially because the pitch tool uses balls and that makes it a rather tough one to work backwards on too. Like I could deal with the taper angle calculation but as soon as you get different size balls in the equation it makes it really tough to calculate. I'm sure I could do it but I'm thinking you are right and ill just write a work around in our procedure. Maybe just ensuring that the distance doesn't change over time due to wear.