SKF TMAS Stainless Steel Machinery Shim Kits, Pre-Cut

Pre-cut shims for vertical machinery alignment

Accurate machine adjustment is an essential element of any alignment process, and the foot shims under a motor or pump are where that adjustment finally happens. The SKF TMAS series offers single slot pre-cut shims in five sizes and ten thicknesses. SKF makes them from high quality stainless steel (grade 304S31), which allows re-use, and describes them as fully de-burred, easy to fit and remove, held to close tolerances and marked with the thickness on every shim.

Pre-cut shims are supplied in packs of 10, and complete kits are available. Using proper shims instead of cut-up tin or stacked washers gives a flatter, more repeatable support, fewer shims in the stack and a thickness you can read at a glance.

Technical specifications

Kits and sets

The leaflet lists complete assortments. TMAS 50/KIT, TMAS 75/KIT and TMAS 100/KIT each hold one size: 20 shims of each thickness from 0.05 to 1.00 mm and 10 shims of 2.00 mm. TMAS 340 combines the 100 and 125 mm sizes, TMAS 380 the 50 and 75 mm sizes, TMAS 360 the 50, 75 and 100 mm sizes in thicknesses from 0.05 to 0.50 mm, TMAS 510 the 50, 75 and 100 mm sizes, and TMAS 720 the 50, 75, 100 and 125 mm sizes. Check the exact quantities in the table in the leaflet before choosing, because the sets differ in thickness coverage.

Selecting shim size and stack

Choose the shim whose area covers the machine foot, and keep the stack as short as practical by combining a few thicker shims with a thin one for fine correction. This listing is on the flagship TMAS 100/KIT; other sizes and codes are quoted on request. The shims complement laser tools such as the SKF TKSA 41, which calculate the shim values to add or remove. Alignment tools are grouped under Portable Test & Measurement. Before ordering, confirm foot dimensions, the thicknesses you need and whether you want loose packs or a kit.

Shim handling also affects the result. Clean the foot and base so no debris sits between shims, avoid stacking more than a handful of shims under one foot, and do not mix thick damaged shims with new ones. Because the thickness is marked on each shim, measure the stack after fitting and record it for the next overhaul. Stainless steel shims resist corrosion, which matters on coastal sites and washdown areas.

Preparing the machine base

Shimming can only be as good as the surfaces it sits on. Before any alignment work, remove old rusted shims, scrape off paint runs, dirt and grout residue from the baseplate pads, and file down any burrs around bolt holes. Check for soft foot by loosening one hold-down bolt at a time and measuring the movement with a dial indicator or the alignment system; a foot that lifts when released must be corrected with shims before the actual alignment moves are made, otherwise the machine will be distorted when the bolts are tightened.

Make sure the hold-down bolts pass freely through the slot of the shim. The single-slot design lets the shim slide in around the bolt without the bolt being removed completely, which saves time and keeps the machine roughly in position while adjustments are made.

Working through an alignment

Take the vertical correction values from the alignment tool and select shims from the kit to build each stack, starting with the thicker shims and adding thinner ones for the final correction. Insert each stack fully so that it supports the whole foot rather than just the edge. After tightening the bolts in a consistent sequence, measure the alignment again, because tightening can change the result slightly. Repeat until the readings are within the tolerance agreed for the machine, then record the final shim stack under every foot.

Kit housekeeping

Return unused shims to their correct compartment immediately after the job, keep bent or damaged shims out of the kit, and replenish thicknesses that run low so the kit remains complete for the next technician.

Using shims in Oman and GCC plants

Pumps, fans and compressors in the region often operate at high ambient temperature and, at coastal sites, in salty and humid air. Carbon steel shims under such conditions can corrode, swell and lose their exact thickness, which upsets alignment over time. The 304S31 stainless steel noted above resists this better, but it is still sensible to inspect shim packs during overhauls and clean away any deposits.

Thermal growth is another regional consideration. A machine aligned cold on a mild morning may move as it reaches operating temperature under full summer load. Where the equipment supplier provides thermal offset values, apply them during alignment, and check alignment again after the machine has run under normal conditions. Fine sand blown into machine rooms should be cleaned from the base before shims are fitted, since even a thin layer of grit between shims adds an unknown thickness.

Selection checks before ordering

Measure each machine foot and the bolt diameter before choosing a shim size, so that the shim supports the full foot area and the slot clears the bolt. Review recent alignment reports to see which thicknesses are used most often on your equipment, since these tend to run out first. For maintenance teams that cover many different machines, a kit covering several sizes is usually more practical than loose packs, while a workshop dedicated to one machine type may prefer packs of the specific sizes it uses. Note the quantities required by thickness on the enquiry so the offer can be matched precisely.

Documents and quotation

The SKF leaflet with all codes and kit contents is attached. Send us the codes and quantities and the delivery point, and we will provide a quotation.