Dear connections, I am using Siemens NX & I have a problem in assembly, I tried making a separate part file by using spline curves, but in assembly after using constraints, the parts has interference (using clearance browser) between them as shown in fig 1. I tried using ''sew'' command also, but failed to achieve. Q) My question is how can I extract a part model from that cut-out space ( by pull face) to fill that space in assembly as a separate part file (I want to make perfect contact in order to perform heat transfer calculations for conductance between both parts). I tried hard for 3 days, but failing. What is the best procedure to make part out to make it separately from assembly and later assemble the newly made part in the same assembly ?Please find attached images in this message for fig 1 and fig 2.