Roller bearings for rolling mills and continuous casting plants

CR Cuscinetti a Rulli designs and manufactures a complete range of roller bearings intended for use in the typical environments of the steel industry, such as rolling mills and continuous casting plants, sheet flattening lines, sintering plants, and more. In these settings, contamination, vibrations, and heavy loads require robust and reliable solutions.

The range includes: back-up rolls with stub shafts for sheet flatteners, cantilevered and single back-up rolls in inch sizes, backing bearings for Sendzimir and Multiroll mills, four-row tapered roller bearings, pressure rollers, tapered and cylindrical roller followers for conveyors, as well as bushings for cardan joints and related shims.

Production includes both standard models and custom-designed versions, with a high degree of customization to meet specific plant requirements. CR’s engineering approach not only ensures compliance with customer dimensional specifications but also optimizes the operational life and performance of the components.

Stub-shaft back-up rolls for sheet flatteners

Back-up rolls designed for flatteners operating in demanding environments. The outer ring, made of UNI 100Cr6 or 100CrMo7 steel, is hardened to 60±2 HRC, with the option of reducing it to 53–58 HRC. Crowned profile for optimal load distribution. The shaft is available in either through-hardened or case-hardened 18NiCrMo5 steel (UNI standard), always at 60 HRC.

Grease lubrication with inlet/outlet channels and a high-efficiency sealing system. Long-life and stainless steel versions are available. Standard precision class is P0 (normal), with P5 available on request.

Two designs available:

- full complement: high load capacity and performance thanks to multiple cages and a wide working surface;

- with roller cages: advanced solutions with integrated thrust bearings to withstand high axial loads.

Cantilevered back-up rolls for sheet flatteners

Full complement cylindrical roller back-up rolls, designed for continuous operation in critical steelmaking environments. Inner and outer rings are made of through-hardened UNI 100Cr6 steel (60±2 HRC), with an option for reduced hardness between 53–58 HRC. The outer ring is crowned for optimal load distribution.

The inner ring features lubrication channels. Double sealing system: shields and steel snap rings or, upon request, rubber lip seals. Standard precision class is P0 (normal), with P5 also available. Stainless steel versions are available on request.

The series includes two- or multi-row configurations, with integrated spacers in the outer ring, offering high dynamic and static load capacity and good resistance to axial forces.

Single back-up roll in inch size for flatteners

Cylindrical roller bearing in inch design, engineered to withstand heavy radial loads during extended flattening cycles. Rings made of UNI 100Cr6 / SAE 52100 steel, hardened to 60±2 HRC, with integral ribs on the inner ring to absorb axial loads.

Bronze cage (or stamped steel cage for smaller sizes). Grease lubrication via groove on the inner ring. High-efficiency sealing system against dust, scale, and moisture. Standard precision class is P0 (normal), with P5 also available. Stainless steel versions available on request.

Available with a cage or in full complement version, it provides a robust and compact alternative to the tapered roller bearing series.

Backing bearings for Sendzimir-type rolling mills

Cylindrical roller bearings designed for Sendzimir-type cold rolling mills, also suitable for use in straighteners and flatteners. Rings are made of hardened UNI 100Cr6/100CrMo7 steel (60±2 HRC); for some series, the outer ring is made of case-hardened UNI 18NiCrMo5 steel. Reinforced-thickness bronze cages, steel thrust washers, and spacers.

Precision higher than P4, with tight tolerances on height H, classified into 3 or 5 groups. Rings are marked with an arrow indicating the point of maximum thickness. Oil lubrication through multiple holes in the inner ring. Some versions are equipped with non-contact lamellar elastic seals.

Available with or without cages, up to four rows, with integral ribs or side washers. Excellent radial load capacity and compact design.

Four-row Multiroll bearings for rolling applications

Designed for roll necks in high-speed rolling mills, calenders, and presses, four-row Multiroll bearings offer high radial load capacity thanks to the number of rolling tracks. Split design: the outer ring with cage ("R" body) can be mounted separately from the inner ring ("L"), simplifying assembly and maintenance.

Made of hardened UNI 100Cr6/100CrMo7 steel (60±2 HRC), including washers and spacers. Cages made of bronze or, for special applications, steel. Precision class P6/P5, with radial clearance C3 or C4. Stabilized for operation up to 150°C, with versions available for temperatures up to 250°C.

Available in various configurations according to application and maintenance requirements.

Four-row tapered roller bearings for rolling mills

Bearings for roll necks in medium-speed rolling mills, capable of withstanding both axial and radial loads without the need for lateral thrust bearings. Supplied as complete units with cylindrical or tapered bore, allowing for quick roll replacement during maintenance.

Cones and cups are made of through-hardened UNI 100Cr6 steel or case-hardened UNI 18NiCrMo5 steel, with hardness of 60±2 HRC. Spacers are made of hardened steel; cages are made of stamped steel. Rotational precision is P5, with standard dimensional tolerances. Available in both metric and inch designs.

Lubrication is facilitated by external holes and channels. Stabilized for use up to 300 °C, with internal clearances defined according to application and specified in the technical drawing.

Pressure rollers for continuous furnaces and sintering plants

Solid, ready-to-mount bearings designed for continuous furnaces in sintering plants, where they operate at low speeds under high loads with frequent motion reversals. The outer ring, featuring three integral ribs and a wear-resistant surface, and the two-piece inner ring with dedicated ribs, ensure resistance to radial loads and axial thrusts.

Manufactured from through-hardened UNI 100CrMo7 steel (60±2 HRC). Available with bainitic treatment (TB1 or TB2) for increased wear resistance. Stabilized for operation up to 250 °C (S2). Sealing system with VITON o-rings in internal grooves to prevent contamination and lubricant leakage.

Tapered roller followers for coil conveyor systems

Used in conveyors for transporting coils, these roller followers support radial loads and strong axial thrusts, typical of the curved paths in transport chain systems. They are mounted in pre-assembled units with a calibrated central spacer.

Outer ring made of case-hardened UNI 16NiCr4 steel, hardened to 60±2 HRC. Three profile options available:

with double guide flange;

without flanges;

with a single flange.

Double sealing system with steel shields and lamellar elastic rings. Grease lubrication via groove on the spacer.

Cylindrical roller followers for conveyors

Used as support rollers for conveyor belts, especially for coils, they are suitable for high radial loads and environments with heat sources. Cylindrical roller followers are made with an outer ring in case-hardened steel (UNI 16NiCr4, 60±2 HRC) and an inner ring in through-hardened steel (UNI 100Cr6, 60±2 HRC).

Available with three outer ring profiles:

- double guide flange;

- plain surface without flanges;

- single guide flange.

This type of roller is primarily used in steel plants, industrial production lines, and heavy material handling systems. It features protection with steel shields and lamellar elastic rings, grease lubrication via groove on the inner ring, and is capable of absorbing deformation, thermal expansion, and limited axial thrusts. In addition, it offers options for C3/C4 radial clearance and thermal stabilization treatment for operation up to 250°C.

Compared to tapered roller followers, cylindrical roller followers provide greater resistance to radial loads and better performance in high-temperature environments.

Bushings for cardan joints

Bushings for cardan joints are a key component for the rigid coupling of two rotating shafts, ensuring torque transmission. Their design includes optimized radial clearance, which is essential for smooth operation without unwanted noise or vibration. These bushings are made of 100Cr6/100CrMo7 steel, fully hardened to a hardness of 60±2 HRC, ensuring strength and durability.

To facilitate maintenance, a threaded hole at the base can be provided on request, compliant with UNI 7663, for grease fitting installation. Additionally, the system can be completed with durothane shims of various heights, offering flexibility to meet specific application requirements.