Hi, 

The value ranges are to be used when you want to apply different hardware according to a length, example of drawer slides according to the available depth. If you want to apply holes based on material thickness, the easiest way is to use “Materials style” and “Sub-methods – Fitting Links”.

First in Tools > preferences, you can define part names (here on shelves 3 & 4 but we recommend using unused items)

Then define Materials in Styles, Sub-methods

After you can apply specific fittings on each parts

Hope this is helpful!