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Merge two faces


Dear all,


I usually use NX CAD for my work. Many NX CAM users want me to tell them how to merge two faces or how to remove an edge between two faces. First of all I want to know why do they need to do this and also what is the best way to remove an edge between two faces


Thank you in advance

Sina Shojaee

Re: Merge two faces

PLM World Member Phenom PLM World Member Phenom
PLM World Member Phenom

Without more detail on what your models look like it will be difficult to answer.  A lot depends on how the geometry is made in the first place. 


I have seen models from other CAD systems that split "Holes" into two faces.  You can use Synchronous modeling - Optimize Face and "Join" these into one face.  If you are importing a step file there is on option on the import dialog to Optimize the faces.  Just a guess on my part.


If you include a model that will make it easier to understand your issue.




John Joyce, Manufacturing Engineer,
Senior Aerospace

NX Vericut 8.0.3 - Statements and opinions are mine alone and do not reflect
the opinion of my employer or any other member of the human race

Re: Merge two faces

Siemens Phenom Siemens Phenom
Siemens Phenom

You will need to provide more detailed information about what the problem is. Pictures or part files would be helpful.


I'm guessing that the problem may be that there is an unexpected edge between two faces that should be one singular face. This happens sometimes when importing non-NX geometry and the translation causes unexpected output such as a cylinder being split into two halves. In such cases, running Optimize Face on the part geometry often cleans things up nicely.


I can't think of any other cases where getting rid of an edge would be beneficial or even possible.

Re: Merge two faces

Siemens Valued Contributor Siemens Valued Contributor
Siemens Valued Contributor



You may also want to consider the Join Face command in modeling.  If it is a prismatic part, Optimize Face is pretty safe, but on more organic shapes it can sometimes make unwanted changes to topology.  I always start with Join Face and then see if more drastic measures are needed.  Replace Face from the Synchronous menu is another way to combine faces, but as already mentioned, your starting geometry and use case will have a lot to do with what solution I would suggest.


Hope that helps,



Re: Merge two faces

@Sina and OP
I agree about Optimize Face; sometimes it removes too much.

Join is my typical go-to command lately.
NX 12.0.2

Re: Merge two faces

Valued Contributor
Valued Contributor

Hello @Sina , 


How to remove an edge between two faces? : You can use through curve mesh command by using the edges of those faces to merge two faces. I think, there is no best way in case of doing CAD. It depends on the data.


First of all, I want to know why do they need to do this? : For example, in Contour Surface Area operation you need to define surface/surfaces, those are drawn by through curves/through curve mesh/...  So NX can understand the grids of this surfaces according to U/V directions. So, the toolpath will be more accurate and you can avoid the engage/retract moves by defining one surface. 



Cad/Cam Engineer




Re: Merge two faces

I am completing my transition to 12 and noticed that Join Face is deprecated.  In my previous post I mentioned I prefer Join but I don't want to mislead anyone if it is going to be obsoleted in the near future.  I should probably transition to Optimize anyway; it appears it has been enhanced since I last used it...

NX 12.0.2

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