Legs (slides) for the table made of steel

Coffee table welded from 18x18 profiles - it scratched the floor when moved. 
And on the carpet - it was hard to move it. I got these legs. 

Steel profiles that I bought to build a table - they were supposed to be 18mm x 18mm, in reality they were 18.4 x 18.2mm, after painting, etc., there was a little more - the model here is about 18.5mm thick, fits perfectly on my profiles. 
The legs should be screwed to the profile from the bottom, using e.g. self-drilling screws. 

There are two files - for a straight leg, and for a fork (joining) of the T style. I use only straight on my table. 
I recommend printing on one of the sides - the print will be much stronger in this plane than if it were printed as it stands.