anglais vers français Technique / Génie Ordinateurs : logiciels CAD

I am looking for a general/standard translation of "cut-piece" in computer aided design.
In the software I am translating, I believe it refers to "coupes" ie sections of a structure which will be assembled on site, but not sure. It could also be a term for item ? (article)?
First, we select the cut-piece we want to edit by clicking with left mouse button on it ("Graphic mode" is set to "Select cut-piece to trim"). Then we change "Graphic mode" to a trimming mode (e.g. "Determine trimming line by two points") and choose two points of the trimming line by two mouse clicks on desktop (mouse mask changes to "axial cross"). Button "Modify active cut-piece" confirms the selection and entered data and performs the function.

Button "Restore original cut-pieces" restores original shape of cut-pieces.