Cylindrical roller bearing

radialresinfor machine tools

Overview
NTN has developed a cylindrical roller bearing in the ULTAGE series for high-speed, heavy-cutting machine tool spindles. Under grease lubrication the bearing achieves an operating life more than 25 times longer than conventional products while combining high rigidity and a dmn of 1.15 million, enabling transition to grease lubrication for spindles and supporting reduced maintenance and improved equipment availability.

Key advantages

• Operating life under grease lubrication more than 25 times that of conventional products (NTN testing).
• Industry-leading high-speed rotational performance: dmn = 1.15 million (≈30% improvement vs. conventional products).
• High rigidity for heavy cutting through optimized large rollers and roller count while retaining high-speed capability.

Development background
Demand for machine tools now requires both higher-speed machining and the rigidity to handle high-precision and heavy-cutting operations. Multitasking machine tools in particular need spindle bearings that balance high-speed performance with stiffness. At the same time, manufacturers seek improved energy efficiency and lower maintenance to support carbon neutrality; adopting grease lubrication can reduce energy use but historically reduced bearing life at high speeds. This product addresses those needs by extending life under grease while preserving rigidity and speed.

Technical approach and features
NTN adopted a newly developed resin retainer and optimized its shape to enable use of larger rollers that provide the rigidity needed for heavy cutting while still achieving high dmn. The retainer's asymmetric structure improves grease distribution so lubricant components reach necessary internal areas, extending operating life. The bearing also supports air-oil lubrication and has improved oil supply performance through optimized flow paths.

Figures and comparative results
Tests under grease lubrication show operating life significantly longer than conventional products (reference: bearings with brass retainers). High-speed tests confirm dmn = 1.15 million while maintaining rigidity required for heavy-cutting applications.

Features of the newly developed product

• Long operating life: >25× conventional products under grease (NTN test basis).
• High-speed performance: dmn = 1.15 million (≈30% improvement versus conventional products).
• High rigidity: large, optimized rollers and roller count designed for heavy cutting.

Applications
Machine tool spindles: multitasking machines, machining centers, lathes.

Exhibition
Product debut at JIMTOF2026 (The 33rd JAPAN INTERNATIONAL MACHINE TOOL FAIR), Tokyo Big Sight, Oct 26–31, 2026.

Notes

• ULTAGE is the name of NTN's next-generation bearing series (from "Ultimate" + "Stage").
• Operating life comparison referenced against bearings using brass retainers.
• dmn = bearing pitch circle diameter (mm) × rotational speed (min^-1).

Technical specifications

• Series: ULTAGE
• Product type: Cylindrical roller bearing for high-speed, heavy-cutting machine tools
• Operating life (grease): >25× conventional products (NTN testing)
• High-speed performance: dmn = 1.15 million (≈30% improvement)
• Retainer: Newly developed resin retainer with asymmetric structure for optimized grease distribution
• Rigidity: Large rollers with optimized dimensions and quantity for heavy cutting
• Lubrication compatibility: Designed for grease lubrication; compatible with air-oil lubrication; optimized oil supply performance
• Primary applications: Machine tool spindles (multitasking machines, machining centers, lathes)