Cylindrical roller bearings adopt a matching structure of straight cylindrical rollers and parallel raceways with exceptional radial load capacity, mainly bearing pure radial loads. Partially ribbed versions withstand limited unidirectional axial force. Separable inner and outer rings enable independent disassembly for easy installation, overhaul and shaft replacement. Their limiting speed exceeds tapered roller bearings, balancing high-speed operation and heavy-load capacity. Four basic configurations are available: NU (inner ring without ribs), NJ (single inner rib), NUP (thrust ribbed), NF (outer ring ribbed), plus reinforced double-row and four-row variants. Widely used for high-power industrial motors, gear reducers, metallurgical rolls, fan spindles, air compressors, heavy machine tool spindles and mine rollers.

Main model classification: single-row basic types NU, NJ, NUP, NF; double-row precision spindle series NN, NNU; four-row rolling mill dedicated series. Two cage types: brass cage for high speed, stamped steel cage for heavy industrial loads.

Compared with deep groove ball bearings, radial rated load increases over 3 times with anti-deformation performance under heavy load. Against tapered roller bearings, they deliver superior high-speed performance and lower heat generation for long-duration continuous high-speed heavy-load operation. Drawback: basic NU models have no axial positioning capacity and require matched locating bearings; unable to resist severe axial impact loads.

High-power variable-frequency motors, steel rolling mills, large gearboxes and high-pressure blowers run under high rotating speed, sustained heavy radial compression, circulating lubricant erosion and oil-dust contamination. Inferior cylindrical roller bearings suffer out-of-round rollers and uneven raceway straightness, causing resonant howling at high speed and roller edge fracture from stress concentration. Thin cages rupture under high centrifugal force. Insufficient quenching hardness on ribs leads to edge chipping under minor axial force. Low overall precision triggers rotor scraping in motors, abnormal gear meshing shock in gearboxes and texture defects on steel plates from rolling mill vibration, resulting in costly production line downtime.

NMT cylindrical roller bearings cover full lineup including single-row standard, double-row precision spindle and four-row rolling mill heavy-duty models. Manufactured with high-purity vacuum-degassed bearing steel via integral quenching for stable hardness. Super mirror finishing on raceways and rollers strictly controls cylindricity tolerance for even load distribution without edge overload. Solid brass cages serve high-speed precision spindles while stamped steel cages are cost-effective for industrial heavy loads. Thickened quenched ribs on NJ/NUP units provide reliable axial positioning. Separable ring structure allows spindle maintenance without complete bearing disassembly. Precision grades P0/P6/P5 are optional; four-row rolling mill bearings are pre-matched before delivery to guarantee roll coaxiality. All dimensions comply with national standards for direct replacement of original bearings for motor assembly, reducer overhaul, metallurgical roll maintenance and large fan retrofitting.

High-end industrial transmission, metallurgical rolling and high-speed spindle equipment are evolving toward higher speed, heavier load, extended maintenance-free cycle and low-vibration high-precision operation. Conventional inferior cylindrical roller bearings feature poor geometric accuracy, weak rib strength and unstable cages at high speed, leading to severe vibration, cage breakage and rib spalling under high-speed heavy load. They fail to meet demands such as 24-hour full-load operation of variable-frequency motors, continuous rolling of steel mills and long-term heavy-load transmission of large reducers. The market demands cylindrical roller bearings with high precision, rigidity and high-speed stability.

Contour crowning on all NMT rollers eliminates edge stress concentration and corner fracture at high speed. Mirror superfinishing on raceways stabilizes lubricant film formation to drastically reduce friction heat at high speed. Reinforced quenching on ribs doubles anti-wear positioning performance. Optimized flow channels on cages ensure smooth grease circulation to avoid local oil starvation and dry friction. Clearance grouping for precision bearings accommodates spindle thermal expansion to suppress high-speed vibration.

All finished bearings pass cylindricity inspection, high-speed temperature rise endurance test, radial rigidity load test and rib impact abrasion test to eliminate defective units with excessive geometric tolerance, heat treatment flaws and poor dynamic balance, ensuring rigid and stable operation of high-speed heavy-load spindles.

Core Product Advantages

Straight cylindrical roller structure delivers ultra-high radial rigidity to prevent outer ring deformation under heavy load for outstanding supporting stability.

Separable inner/outer ring structure avoids full bearing disassembly during spindle overhaul or shaft replacement for greatly improved maintenance efficiency.

Versatile configuration selection: NU floating design compensates shaft thermal elongation; NJ/NUP enables axial positioning for matched floating-end & fixed-end bearing layout.

Double-row precision units feature superior dimensional accuracy and dynamic balance for low-vibration high-speed operation of machine tool and rolling mill spindles.

Solid brass cages resist centrifugal rupture for durable long-term high-speed rotation.

Roller end crowning eliminates edge stress concentration to prevent corner breakage failure.

Reinforced rib quenching enables moderate axial load bearing for simplified bearing pairing layout.

Standard national dimensions support direct interchange with original bearings for industrial motors, reducers and rolling mills.

Typical Application Scenarios

Spindle support bearings for high-voltage high-power variable-frequency motors and large asynchronous motors; bearings for hard-tooth surface gear reducers, planetary gearboxes and shield machine reducers; four-row cylindrical roller bearings for hot/cold rolling mill rolls and continuous casting roller tables; spindle bearings for large centrifugal fans, blast furnace blowers and air compressors; precision spindle bearings for heavy-duty machine tools, gantry milling machines and grinders; support bearings for mine heavy rollers, vertical cement mills and paper press rolls.

Quality Assurance

NMT cylindrical roller bearings adopt vacuum-refined bearing steel with extremely low non-metallic inclusion content to extend fatigue service life. Rollers are sorted by dimension to minimize dimensional deviation within one bearing for uniform load distribution. Cage options include solid brass cage (high-speed precision) and stamped steel cage (industrial heavy load) for targeted selection. Compatible with circulating oil lubrication and grease lubrication. Single-row bearings are flexibly combined as fixed-end plus floating-end installation; double-row and four-row integrated assemblies are ready for direct mounting. Fully applicable to continuous high-speed rotation, heavy radial load, mild axial positioning and circulating lubrication environments.

Product Range

Single-row: NU, NJ, NUP, NF series; Double-row precision spindle: NN, NNU series; Four-row rolling mill special FC, FCD series; Precision grades P0, P6, P5.

Brand Strength

NMT Japan resolves four major failure modes of traditional cylindrical roller bearings: roller edge fracture from stress concentration, high-speed cage damage, positioning rib abrasion and excessive vibration from poor raceway precision. Process upgrades including roller end crowning, mirror superfinished raceways, high-strength rib heat treatment and separable modular structure achieve high rigidity, stable high-speed operation and easy maintenance with long service life. We supply high-speed heavy-duty cylindrical roller bearings for motor manufacturers, reducer factories, steel mills, fan manufacturers and heavy machinery maintenance providers to reduce spindle abnormal vibration & noise, production shutdown from bearing fracture, surface defects on rolled products and impact damage to reducer gears, cutting downtime losses and parts replacement costs for continuous production equipment.