LH thread designation 1

[Dave K]

Other than ASME B1.1-2003, are there any specs that denote the "LH" at the end of a thread callout, to specify it is a left handed thread?

-Dave

NX 9, Teamcenter 10

 

[3DDave]

FED-STD-H28

Available free from

http://quicksearch.dla.mil/

Use the Document ID field to search for H28.

 

[CoryPad]

ISO 965-1

 

[CheckerHater]

Practically every single standard in ASME B1.1 family like shown on the picture.

 

[Dave K]

Thanks. I'm building a case, to show an enhancement is needed in some software.

-Dave

NX 9, Teamcenter 10

 

[looslib]

Dealing with NX, just modify the thread callout tables for the LH designation, or build a separate table for LH threads. The thread tables are generic and work for LH or RH threads. The software has no method to determine if it is RH or LH, that is usually added after the hole has been modeled into the part with appended text.


"Wildfires are dangerous, hard to control, and economically catastrophic."

Ben Loosli

 

[Dave K]

Which is what I don't understand, you have the option to tell NX if the thread is right or left handed, yet it doesn't use that information, if the thread is symbolic. I don't like relying on the user, to remember to append that text.

-Dave

NX 9, Teamcenter 10

 

[3DDave]

Not a worry. When the shop puts in a RH tap and the CNC drives it as a LH tap, the difference will become quite obvious.

Seriously - NX doesn't drive the note from a pre-determined table of acceptable threads?

 

[3DDave]

Forgot to mention - there's a good Siemens: UG/NX Forum here;

http://www.eng-tips.com/threadminder.cfm?pid=561

They may have better help for what is an application specific problem.

 

[Dave K]

I posed the question here, not for help with NX, but to gather information on specs, so that I can submit them to Siemens, in support of my "issue".

-Dave

NX 9, Teamcenter 10

 

[looslib]

I would suggest asking in the NX forum. John Baker has great knowledge of NX and is an active participant in that forum. I think he wrote most of the original tables used for the tap-drill information.

3Dave, yes NX does use tables to generate the notes for tapped holes. I used to modify them to use the tap drill that our shop used instead of what Siemens thought they should be using. Did the same for the Pro/E tables.



"Wildfires are dangerous, hard to control, and economically catastrophic."

Ben Loosli

 

[Dave K]

Thanks Ben. John is already aware of this issue, and submitted his own PR on it too.

-Dave

NX 9, Teamcenter 10