SKF TMFT Bearing Mounting Kit: How to Mount Cold

The SKF bearing mounting kit TMFT is a tool designed to install small and medium bearings cold, without resorting to direct blows on the bearing. It is intended for maintenance workshops and production lines where bearings are mounted with a fit on the shaft or in the housing. The kit includes a series of impact rings and sleeves that are combined according to the bore diameter and the outer diameter of the bearing.

The SKF TMFT series groups bearing mounting tools that cover a wide range of bore and outer diameter sizes. Codes such as TMFT 24 or TMFT 36 identify kits with different combinations of rings and sleeves.

The operating principle is simple: the impact ring rests on the bearing ring that is mounted with a fit, and the sleeve transmits the hammer blow evenly. This prevents the force from passing through the rolling elements, which is the most common cause of damage during mounting. At MR we supply these SKF kits and help you choose the right model for your application.

Hitting a bearing directly with a hammer or mallet is one of the main causes of premature failure. The point impact on the outer or inner ring can generate marks, dents or microcracks that later lead to vibration and noise. Also, if the blow is transmitted through the rolling elements, the raceways are damaged and the bearing loses precision.

The SKF bearing mounting kit TMFT solves this problem by interposing an impact ring that distributes the force over the entire circumference of the ring being mounted. The sleeve, in turn, receives the hammer blow and transfers it to the ring in a controlled manner. In this way, the bearing slides smoothly onto the shaft or into the housing without receiving direct impacts.

In practice, cold mounting with a kit is fast and safe for small bearings, where the fit is not so strong as to require heating. It is a tool that every maintenance workshop should have on hand, because it reduces the risk of damaging expensive parts and avoids plant downtime due to avoidable failures. We distribute SKF TMFT kits so you can work with the right tool.

The choice of ring and sleeve depends on two measurements: the bore diameter of the bearing and its outer diameter. The impact ring must rest on the ring that is mounted with a fit: if the bearing is mounted on the shaft, the ring rests on the inner ring; if it is mounted in the housing, it rests on the outer ring. The sleeve must have an inner diameter slightly larger than that of the shaft or bore, so that it does not interfere.

Therefore, it is advisable to have the bearing code on hand before starting: with the bore and outer diameter visible, the choice of ring and sleeve is straightforward. If the kit does not have a combination that rests well on the correct ring, it is not advisable to improvise with another part.

A common mistake is choosing a ring that rests on the wrong ring, which can damage the bearing or make mounting more difficult. Another mistake is using a sleeve that is too large, which does not center the blow well and can misalign the bearing. If you have doubts, at MR we help you select the correct kit according to the code of the bearing you are going to mount.

Before starting, verify that the shaft and housing are clean, free of burrs or marks. Apply a thin layer of oil or grease on the mounting surface to facilitate sliding. Place the bearing in position, making sure it is aligned with the shaft or housing. Poor initial alignment can jam the bearing and force you to hit harder.

Select the impact ring that rests on the ring with the fit and the corresponding sleeve. Place the ring on the bearing and the sleeve on the ring. Hit the sleeve with a nylon or rubber hammer, with gentle and even blows, turning the sleeve a little between blows. This helps the bearing enter straight and without getting stuck.

When the bearing reaches its final position, verify that it is well seated against the shaft shoulder or the bottom of the housing. If the bearing does not enter with gentle blows, do not increase the force: it may be that the fit is too strong for cold mounting, or that there is dirt or a burr. In that case, it is advisable to check the measurements and consider heating the bearing.

Cold mounting with a kit is ideal for small and medium bearings with not very strong fits. But when the fit is tighter, or the bearing is larger, the effort required to mount it cold can be excessive. In those cases, it is recommended to heat the bearing to expand the inner ring so that it enters the shaft easily.

Heating is done with an induction heater, which is the safest and most controlled method. A bearing should never be heated with a torch or direct flame, because it can alter the heat treatment of the steel and damage the seals or the cage. The heating temperature must be moderate and never exceed the limit indicated by the manufacturer.

The TMFT kit does not replace the induction heater, but is complementary. For small bearings, the kit is faster and more practical, and does not require waiting for the bearing to cool. At MR we supply SKF mounting kits and help you define which method is best in each case.

TMFT kits are identified by their code, such as TMFT 24, TMFT 36 or TMFT 36 A. Each code corresponds to a kit with its own combination of rings and sleeves, so it is always best to order with the full code.

It is important not to mix parts from different kits, because the diameters may not match and the ring would end up resting where it should not. Keeping each kit complete and organized makes selection quick at the time of mounting.

To get a quote for a TMFT kit, it is best to indicate the range of measurements of the bearings you are going to mount, or directly the kit code if you already know it. At MR we quote it and respond promptly, with advice on which is most convenient for your workshop.

One of the most frequent mistakes is hitting with too much force or with a steel hammer, which can damage the sleeve or the impact ring. Always use a nylon, rubber or leather hammer, and controlled blows. Another mistake is not verifying that the impact ring rests correctly on the ring with the fit, which can misalign the bearing.

It is also common not to clean the shaft or housing well before mounting. Dirt, rust or burrs can scratch the surface and hinder the entry of the bearing. A thin layer of lubricant helps, but does not replace cleaning. And you should never force a bearing that does not enter with gentle blows: something is wrong, and continuing to hit only makes things worse.

Finally, store the kit in its case, with each part in its place. Loose parts get lost or mixed, and then it is difficult to know which ring corresponds to each size. A well-maintained kit prevents costly damage to bearings. At MR we help you choose the correct TMFT kit and use it safely.