Napoleon Engineering Services Announces Rolling-Contact Fatigue and Wear Testing

October 4, 2017 – Olean, NY — The largest independent bearing testing and inspection facility in the United States, Napoleon Engineering Services (NES) has announced their advancements in proven test technology offering expanded test opportunities for low-cost, proof-of-concept research.

Ball-on-Rod RCF Tester

The NES Three-Ball-on-Rod Tester represents one of the most economical rolling contact fatigue proof of concept tests available in the industry. Testing is performed to evaluate the influence of heat treatment, material, lubricant, and coatings on fatigue life.

The advantage of the NES tester is that run times are short and a single rod specimen can provide many failure data points thereby containing overall project costs. High stress cycle accumulation per revolution and stress levels up to 900 ksi (6.2 GPa) provide many options to the test engineer. NES has designed these RCF testers with oil heaters, lubricant flow control, test fixture temperature monitoring and vibration sensors with a dedicated data acquisition and monitoring system to ensure test integrity.

Five-Ball Tester

The NES Five-Ball tester captures many of the intricate mechanics of bearing fatigue making it very attractive for simulation of full scale bearing testing of ball bearings without full scale costs.

The upper drive ball simulates the inner ring, the cup supporting the lower four balls models the outer ring and the four planetary balls replicate the balls in a bearing. Five-Ball testing can be used to qualify ball manufacturers, verify material lot integrity, investigate lubricant effects on fatigue life, study ceramic ball material and process quality, and determine heat treatment life factors. This modern version of the original NASA testers is designed to run at speeds up to 10,000 rpm and stress levels up to 900 ksi (6.2 GPa) on ball diameters up to 1¼”. The NES tester controls lubricant flow, oil temperature, rotational speed and applied load while monitoring support cup temperature and system vibration for automatic shutdown.

Cylindrical Roller Tester

Testing of individual cylindrical rollers outside of a full scale bearing can now be achieved using the NES Cylindrical Roller Tester (CRT). Testing ceramic roller quality or evaluating the influence of crown geometry on roller life can now be done cost effectively and without the risk of inner or outer ring failure. The NES CRT can accommodate 7mm x 7mm rollers up to 14mm x 14mm making it an ideal test bed for aerospace roller geometry and material research and development. Testing of ceramic roller to validate material and process integrity at high stress levels can be achieved on the CRT.   Stress levels as high as 450 ksi (3.1 GPa) can be achieved with multiple stress cycles per roller rotation resulting in short test times without the need for complete bearing testing and resulting ring failures. The CRT allows for validation of material, surface, form, and process integrity for end users, roller manufacturers and bearing manufacturers alike.

NES Fretting Wear Tester

The NES fretting wear tester is based on ASTM D4170 standard test method for fretting wear protection of lubricating greases; however, it is also designed to allow for increased oscillation angles and can be used to validate proof of concept wear solutions under aggressive fretting and oscillating conditions.

The NES fretting wear tester is an ideal platform to evaluate the influence that material, dry film lubricant, coatings, plating, cage material, grease, or manufacturing processes have on wear. The machine tests two thrust ball bearings with an axial load applied at oscillation angles up to ± 30°. This tester provides test results within days with low cost sample preparation.


Napoleon Engineering Services, founded in 1997 in Olean, NY, is a privately-owned, one-stop shop for engineered bearing products, specializing in Bearing Inspection, Bearing Testing and Custom Bearing Manufacturing. Napoleon Engineering Services prides itself on providing bearing solutions to a vast number of industries and is the largest independent bearing inspection and testing facility in the United States. NES can be reached at (877) 870-3200 or through

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