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Test protocol

SNR systematically qualifies each supplier's perfor-mance, and each steel's quality, through test ben-ches referred to as "FB2". In fact, we test the intrinsic performance of the material in bearing applications, totally irrespective of all parameters which could be attributed to bearing geometry. The test consists of trying a large number of samplesunder high loads and at 1,500 rpm, and deducing the service life (L
Axial load Speed 1,500 rpm Test specimens 10 ) reached by 90% of the samples.
Test specimens

Heat treatment: protecting against wear

The specific spherical roller bearings heat treatmentguarantees dimensional stability, even at very high temperature. It provides the bearing with itsintended operating properties: resistance to failureand wear, reliability. The tempering treatment after quenching provides a martensitic structure, with suitable durability, allowing our bearings to withs-tand extreme operating conditions.
Dimensional stability up to 200°C Life Expansion results from the transformation of residual austenite when present in large quantities.There is virtually no expansion because there is very little residual austenite.Shrinkage due to the development of the martensitic Standard heat treatment Specific SNR heat treatment matrix.2,000 hours Dimensional variation when the bearings are used at high temperature.

Cage surface treatment: optimized lubrication

In the SNR Premier bearings, the steel cages areprotected from corrosion by a phosphate treatmentwhich changes the superficial steel structure,making it porous, so that it acts as an oil pump. Thisguarantees a lubricant film at cage contact with rollers and inner race, thereby limiting friction wear. 7