Common forms of damage and solutions for bearings in rod & bar mills

Jan 13, 2025

FV Bearing specializes in the supply and service of bearings for the wire rod rolling mill industry. 

FV engineers also plan to visit user sites every year to understand the usage of bearings. Being able to promptly identify usage issues and help customers reduce bearing wear and tear.

24036 (34036MBW33 or 24036CCW33) spherical roller bearings and four-row cylindrical roller bearings (313812, R313812 & L313812) are widely used in rod/rebar steel mills.

The most common forms of damage to these bearings include outer ring cracking, cage fragmentation, roller fragmentation, and bearing raceway burns. 

How can we reduce the occurrence of such problems? Firstly, we need to study based on the frequency of bearing usage and operating conditions. 

The 24036 bearings and corresponding rollers will be frequently replaced. The frequency increases with the number of times bearings and rollers are replaced. 

We have found some commonalities in a large number of damage cases. 1. The outer ring of the bearing is prone to annular cracking. Even if many brands of bearings are used instead. The same type of damage still occurs. And many users will be confused by the damaged form.

Inexperienced users may think that the bearing rings are not strong enough and the cage and rollers are not strong enough based on intuitive phenomena.  But in fact, the vast majority of bearings  are innocent. 

There are three fundamental reasons: 

1. The installation and fitting of the bearings are incorrect. The inner ring of the bearing has an interference fit. The bearing needs to be heated to around 100 degrees Celsius before it can be smoothly installed onto the roll neck. After installation. The radial clearance of the bearing has been compressed to C2~CN at room temperature. But many users install bearings incorrectly. 

2. Excessive wear of the roll neck. Excessive wear on the diameter and roundness of the bearing housing hole.

This type of wear will result in a decrease in the rated load of the bearing. Reduced impact resistance can lead to bearing ring cracking. The working clearance of the bearing is incorrect. The outer ring of the bearing has lost good support. 

3. Low quality and excessive lubricating grease increase the working resistance of bearings, accelerating the temperature rise of bearings Installation engineers and mechanics are unaware of the interchange tolerance for the inner raceway diameter of cylindrical roller bearings. Mixing bearings of different brands and exchange standards. And there was no secondary confirmation of the initial installation clearance after the bearing installation. This operation will cause the bearing to have either too little radial clearance or too much clearance.

If the clearance is too small. Bearings generate severe heat during operation. If the clearance is too large, the load on the bearing will decrease, and the wear of the bearing parts will intensify, seriously reducing the bearing life.

FV engineers can provide free installation guidance files for global users. Welcome personnel in the steel industry to contact the sales engineer of FV bearings.

In addition, FV bearings have compiled some of the most commonly used rolling mill bearing models.

We believe that the bearing model you are using must appear in this list.