Although this table is a good starting reference on the proper size of shim to be used, the most important factor is the support of the piece of machinery being shimmed. Please double check the dimensions of the mounting feet and bolt size to insure proper support. The emergence of oversize slotted shims has allowed for the substitution of shims with a small footprint to accommodate a larger size bolt.
Sometimes, this savings has come at the expense of support between the mounting feet and base plate.
Fig. 1 shows a fully supported machine, the shims extend beyond the mounting foot. Fig. 2 shows how using an oversized slot will accommodate the bolt size, but might not provide the proper support. This can lead to vibration problems and more frequent need of shaft alignments.