SKF TMAS machinery shims for machine alignment

Aligning a motor with a pump or a gearbox almost always ends the same way: raising or lowering one of the feet by a few tenths of a millimeter. That vertical correction is made with shims. Because their thickness is known and uniform across the whole surface, they let you add exactly what the alignment tool indicated and repeat the result. With hand-cut sheet metal or improvised packing the support is uneven, soft foot appears and the alignment does not last.

Pre-cut shims have a slot that fits around the anchor bolt: they go in and come out by loosening the bolt, without removing the machine. SKF TMAS shims are made of stainless steel and have the thickness marked on them, so there is no need to measure them one by one.

The shim size comes from the size of the foot and the anchor bolt: the shim must cover the support well and the slot must clear the bolt. In the TMAS series the first number of the code is the shim size in millimeters (50, 75, 100, 125 and 200) and the second is the thickness in hundredths of a millimeter: a TMAS 100-050 is a 100 mm shim 0.50 mm thick, and a TMAS 75-200 is a 75 mm shim 2.00 mm thick.

When correcting, use as few shims as possible: one thick and one thin shim are better than a stack of thin ones, because every shim adds a joint that can settle. That is why you need several thicknesses at hand, from 0.05 mm to 3.00 mm.

If you align often, a kit is the practical choice. The TMAS 340, TMAS 360, TMAS 510 and TMAS 720 are carrying cases with an assortment of sizes and thicknesses; the TMAS 50/KIT, TMAS 75/KIT and TMAS 100/KIT are sets in a single size. Shims by size and thickness are for replacing what gets used up. Tell us the foot and bolt sizes of your machines and we will tell you which kit fits.

Before measuring, clean the supports and remove old, rusty or bent shims. Correct soft foot first: loosen one foot at a time and shim the one that lifts. Then measure the alignment, place under each foot the thickness the tool indicates, tighten the bolts in a cross pattern and measure again. Write down what ended up under each foot: it saves time at the next maintenance.