How to mesh line in a step file structure

[kmerbcn]

Hello

I am very new into gmsh. I have followed the examples and if i do my own geometries with gmsh I can control the mesh rather good.
Nevertheles, I am a bit lost as soon as I import a step file with GMSH and start meshing.
I would like to mesh 1D lines in a controlled manner in the same way as you do with the lc parameter in the scripts.
Because now in a step you can't define points and lines in the same way.
How do set-up which lines are coarser and which ones are thinner?

I can send the step file geometry. Sorry for this stupid question
DI19368_copia_2.zip