Spanish to English Tech/Engineering Mechanics / Mech Engineering

This is from a document describing the facility for washing fabrics using special techniques.

"Esta estructura ha sido construida en perfil estructural de acero galvanizado, tipo tubo cuadrado de (100x100x2 esp.) para las columnas, provisto de placas base para fijación tanto al suelo como a la cubeta y completamente arriostrado con perfil angular de (40x40x4 esp)."

Any ideas what "esp." means here, please? Is it "especificación" (in which case, would I just leave it out since it is obvious)?

Many thanks for any help