How to Select Four-Row Cylindrical Roller Bearings for Rolling Mills

Rolling mills place extremely high radial loads on roll-neck bearings. At the same time, the bearings must maintain stable running accuracy and allow convenient inspection or replacement during roll changes. For these reasons, four-row cylindrical roller bearings are widely used in hot rolling mills, cold rolling mills, bar mills, wire rod mills and other metallurgical equipment.

Selecting a rolling mill bearing involves more than matching a bearing number. The structure, dimensions, internal clearance, precision, lubrication and actual operating conditions should all be checked before a replacement is confirmed.

Why Four-Row Cylindrical Roller Bearings Are Used in Rolling Mills

The four-row roller arrangement provides a large contact area within a compact radial section. It offers high radial load capacity and rigidity, while the separable components make mounting, inspection and maintenance more convenient during roll changes.

• High radial load capacity for heavy rolling loads

• High rigidity and stable running accuracy

• Separable components for easier mounting and inspection

• Suitable for frequent roll replacement

• Applicable to work rolls, intermediate rolls and backup rolls

Four-row cylindrical roller bearings mainly support radial loads. Depending on the roll-neck arrangement, a separate bearing may be required to locate the shaft axially.

FC, FCD and FCDP Rolling Mill Bearing Series

1. FC Series

   FC series bearings generally use a four-row cylindrical roller structure with two outer rings and one inner ring. They provide high radial capacity and are commonly used at non-locating bearing positions in rolling mills.

2. FCD Series

   FCD series bearings use a separable four-row design. Their rings and roller assemblies can be separated more conveniently during mounting, inspection and roll replacement, making them suitable for equipment requiring regular maintenance.

3. FCDP Series

   FCDP series bearings are intended for heavy-duty rolling mill applications. They are often considered for larger bearings and demanding operating conditions involving load, rigidity and precision.

The final series should be confirmed according to the original bearing number, roll-neck drawing and operating conditions.

Information Required for Rolling Mill Bearing Selection

1. Existing Bearing Number

The existing bearing number is the fastest reference for confirming a replacement. Commonly requested models include FC3652168, FC4058192, FC4462192, FC4666206, FC5274220, FC5678220, FC5882240 and FC6084240. Additional FC, FCD and FCDP models are available according to the required dimensions and structure.

2. Bearing Dimensions

Confirm the bore diameter (d), outside diameter (D) and bearing width (B). A similar-looking bearing may have different internal structures, clearances or precision requirements, so dimensions should not be used as the only selection criterion.

3. Roll-Neck or Housing Drawing

A technical drawing helps confirm the ring arrangement, locating and non-locating positions, mounting method, lubrication holes, axial positioning and required tolerances. It is especially important for customized or discontinued designs.

4. Operating Load and Speed

Hot rolling mills, cold rolling mills and wire rod mills operate under different loads and speeds. Approximate radial load, roll speed and working cycle should be provided before the bearing structure and precision grade are confirmed.

5. Internal Clearance

Operating temperature, fit and load all affect the working clearance of the bearing. An unsuitable clearance may lead to excessive heat or unstable operation. The required clearance should therefore be selected according to the equipment design.

6. Lubrication and Working Environment

Confirm whether the bearing uses oil lubrication, oil-air lubrication or grease lubrication. Water, mill scale, dust and elevated temperatures around rolling equipment may also affect the bearing configuration and maintenance interval.

Common Causes of Rolling Mill Bearing Problems

Bearing problems are not always caused by the bearing itself. Common contributing factors include incorrect mounting, contaminated lubrication, unsuitable internal clearance, poor roll-neck accuracy, uneven load distribution and water or scale entering the bearing position.

Inspecting the complete bearing arrangement is usually more effective than replacing a damaged bearing without identifying the operating cause.

What to Include in an Inquiry

• Bearing number and d × D × B dimensions

• Bearing, roll-neck or housing drawing

• Clear photos of the existing bearing

• Rolling mill type and roll position

• Operating speed and approximate radial load

• Lubrication method

• Required clearance and precision grade

• Order quantity

Rolling Mill Bearing Supply from BWK

BWK supplies four-row cylindrical roller bearings for rolling mill applications, including FC, FCD and FCDP series. Standard and customized solutions are available according to bearing numbers, drawings, samples and operating conditions.

Explore our rolling mill bearings for different roll positions and operating requirements.

View our Four-Row Cylindrical Roller Bearings for Rolling Mills, or contact BWK with the bearing number and dimensions for model confirmation and quotation.