Lubricant grease SP-1

for spindlesfor bearingsfor machine tools

Overview
NTN Corporation will begin mass production of its high-speed, long-life grease SP-1 for bearings for machine tool spindles in November 2026. SP-1 maintains stable lubrication under high-speed rotational conditions, enabling extended bearing life and reliable high-speed rotation. Mass production establishes a stable supply for equipment evaluation and supports customers toward formal adoption.

Key Benefits

• Achieves high-speed rotational performance with a dmn value of 2.3 million.
• Contributes to improved productivity through high-speed machining and more stable equipment operation.

Technical summary and testing

• Bearings filled with SP-1 achieved operation at a dmn value of 2.3 million in NTN testing simulating actual machine operation (industry-leading level for grease-lubricated machine tool spindle bearings as of October 2026, per NTN research).
• High-speed rotational durability testing at a dmn value of 1.4 million under severe conditions showed continuous operation for more than 18,000 hours, confirming excellent durability under high-speed rotation.

Background and application
Demand for machining high-precision components (EVs, semiconductors, aerospace) is driving need for higher-speed, higher-precision machine tools and for stable operation with reduced maintenance. Air-oil lubrication is widely used in high-speed ranges but requires auxiliary equipment. Grease lubrication can simplify equipment configuration and improve energy efficiency; SP-1 addresses prior challenges such as grease deterioration and insufficient lubricant supply at high speeds by optimizing base oils, thickeners, and additives to improve lubricant supply performance and maintain stable lubrication during high-speed rotation.

Commercial deployment
Since the development announcement in 2024, NTN has received inquiries from machine tool manufacturers domestically and internationally and has prepared to provide bearings filled with SP-1 for customer evaluation. Mass production begins November 2026. NTN plans proposal activities including participation in JIMTOF2026 and market expansion in Asia (China and other Asian markets).

Notes

• dmn value: indicator of high-speed rotational performance calculated by multiplying bearing size by rotational speed; higher values indicate capability for higher-speed rotation.
• Performance claims based on NTN testing and research (October 2026).

Specifications / technical characteristics

• Product name (commercial): SP-1
• Application: grease for bearings for machine tool spindles
• Mass production start: November 2026
• Achieved high-speed rotation: dmn = 2.3 million (NTN testing)
• High-speed durability test: dmn = 1.4 million, >18,000 hours continuous operation under severe test conditions
• Performance targets: enable high-speed rotation and long bearing life, support stable equipment operation, reduce maintenance person-hours
• Technical approach: optimized combination of base oils, thickeners and additives to improve lubricant supply performance at high speed
• Intended commercial focus: machine tool manufacturers, Asia (including China) highlighted as key markets