Hot rolling mills, continuous casters and roller tables are core equipment of iron and steel metallurgical production lines. Bearings for roller table supports, auxiliary rolls of rolling mills and continuous casting guide rolls operate under harsh working conditions: continuous heavy-duty operation, impact loads from high-temperature steel billets, deflection of long roller shafts, coaxial deviation during assembly, high-temperature thermal radiation along rolling lines, continuous falling and scouring by massive iron scale, alternating wet and dry conditions from cooling water spray and 24-hour non-stop continuous rolling. The smelting and rolling process of steel requires extremely high continuity, and starting and stopping the production line consumes enormous energy. Once roller table or rolling mill bearings fail and cause shutdown, high-temperature billets cannot be transported and are prone to cooling and scrapping. The whole rolling line has to stop, leading to huge energy loss and production shortage. Ordinary spherical roller bearings cannot adapt to extreme conditions of rolling lines featuring high temperature, dense iron scale and alternating hot and cold cycles. Long conveyor roller shafts bend under billet loads and create angular misalignment. Conventional bearings have insufficient self-aligning margin, resulting in edge stress concentration and rapid fatigue pitting and spalling. Continuous high-temperature radiation in rolling areas causes conventional grease to oxidize, coke and carbonize rapidly under heat and lose lubricating performance. Iron scale falling from hot billets is high-hardness with sharp edges, continuously scouring sealing components. Simple seals wear out quickly. Scale fragments penetrate into bearings and form hard abrasive media that continuously erode raceways and rolling elements. Cooling water spray on roller tables and repeated thermal alternation accelerate seal aging and cracking. These challenges have long troubled metallurgical machinery manufacturers and steel mill maintenance teams.

Focusing on transmission supporting field for metallurgical steel rolling equipment, Japan NMT specially develops high-temperature and iron-scale resistant spherical roller bearings dedicated for hot rolling mills, continuous casters and roller tables to solve industry pain points including shaft deflection and eccentric load of rolling equipment, high-temperature thermal radiation, erosion by iron scale dust, alternating wet-dry conditions caused by cooling water and limited service life under long-cycle continuous rolling. Taking advantage of optimized double-row spherical roller self-aligning load-bearing structure, combined with five core upgrades including heat-stabilized bearing alloy steel for metallurgy, profiled rollers for high-temperature conditions, reinforced cages, optional multi-layer labyrinth high-temperature scale-proof composite seals and special clearances for high-temperature heavy loads, the bearings fully compensate deflection of long roller shafts and assembly misalignment and block ingress of iron scale and cooling water. Suitable for harsh working conditions of hot rolling lines producing plates, sections, bars and wires, they fundamentally relieve fatigue spalling under misalignment, high-temperature lubrication failure, abrasive wear by scale and thermal damage of seals, stabilize rotation precision of all roller systems and guarantee long-cycle continuous stable operation of steel rolling lines.

Core Product Advantages

1. Reliable self-aligning performance to adapt to deflection deformation of long conveyor roller shafts: Spherical raceways matched with profile-optimized double-row spherical rollers allow reasonable angular offset, absorb bending deformation of long roller shafts under billet loads, avoid unilateral edge loading of rollers and greatly reduce stress concentration, improving eccentric load operation defects of long roller systems.

2. Ultra-high radial load capacity to withstand billet impact and continuous alternating loads: Symmetric double-row roller bearing structure provides sufficient contact area, steadily sustaining continuous radial heavy loads and bidirectional axial loads. It buffers intermittent impact loads generated during transportation of hot billets and adapts to frequent load fluctuation of rolling mills and continuous casting roller tables.

3. Thermally stable special bearing substrate to resist continuous high-temperature radiation on rolling lines: Selected high-purity heat-resistant bearing alloy steel specially for metallurgical rolling equipment undergoes deep stabilized quenching heat treatment with stable metallographic structure under high temperature, restraining high-temperature creep deformation and slowing surface pitting and spalling induced by combined action of high temperature and iron scale.

4. Ultra-precision raceway & optimized roller profile to control frictional temperature rise: Micron-level super-finishing on raceways and smooth profiling on roller ends optimize contact stress distribution, lower frictional heat during operation, slow thermal aging and carbonization of grease under high temperature and reduce continuous running vibration of roller tables.

5. Multiple high-temperature sealing options to block ingress of iron scale and cooling water: Open type and high-temperature labyrinth composite sealed type are available; C3/C4 clearances are preferred for high-temperature conditions. Multi-layer labyrinth anti-scale sealing structures can be configured for high-temperature roller table zones to resist scouring by hot scale and cooling water spray and prevent hard debris from entering bearing housings.

Application Scenarios

Support bearings for guide rolls and segment sections of continuous casters; bearing housing bearings for furnace entry rollers, transport rollers and cooling rollers of hot rolling production lines; auxiliary back-up roll and tension roll bearings for hot rolling mills; roller system supports for bar, wire rod and section mills; heavy-duty transmission supporting positions of complete metallurgical equipment for plate hot rolling and special steel smelting.

Precision Quality Assurance

NMT spherical roller bearings for metallurgical steel rolling series are manufactured strictly in accordance with Japanese heavy metallurgical equipment component standards. Raw materials are inspected one by one via flaw detection. Tests including continuous high-temperature temperature rise durability test, iron scale flushing sealing test, hot-cold cycle fatigue test, alternating impact load durability test and high-temperature dimensional stability test are carried out. Featuring stable self-aligning performance, outstanding high-temperature load capacity and excellent resistance to abrasive wear by scale, the bearings fully adapt to 24-hour continuous rolling conditions with high temperature, dust and alternating wet and dry cycles on steel rolling lines.

Product Range

Standard open-type spherical roller bearings for metallurgy, high-temperature labyrinth scale-proof sealed spherical roller bearings, heavy-duty roller table bearings with reinforced cages, customized large-size spherical roller bearings for metallurgical equipment. Both cylindrical bore and tapered bore mounting types are available.

Brand Strength

Japan NMT focuses on R&D and manufacturing of transmission bearings for heavy metallurgical rolling equipment, specializing in core technologies including optimization of self-aligning structure for long roller shafts, thermally stable heat treatment technology for high temperature, long-life high-temperature scale-proof sealing and control of high-temperature fatigue wear. Supported by complete rolling line condition simulation testing platforms and refined heat treatment production lines for heat-resistant steel, NMT solves common industry pain points of metallurgical bearings such as fatigue spalling caused by long shaft misalignment, grease coking under high temperature, abrasive wear failure by iron scale, billet scrapping and output decline triggered by shutdown, supplying high-load, high-temperature resistant and scale-erosion resistant long-life spherical roller bearing solutions for global metallurgical machinery manufacturers.