
NSK Case Study

Application
Cold Rolling Mill:
Steel Strip
Cost Savings: $28,288
A major steel producer was dissatisfied with the performance of their Four-Row Tapered Roller Bearings installed in their cold rolling mill. Steel shavings from the production process were entering the bearings resulting in a detrimental effect on bearing reliability. NSK performed a detailed on-site analysis of the bearings along with inspecting a failed bearing and lubrication analysis. After thorough review, a recommendation was made to adopt NSK Tough Steel technology which offers an excellent resistance to damage caused by the ingress of contamination.

Cold Rolling of Steel
Key Facts
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Cold rolling mill |
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Damage of the bearings due to ingress of steel shavings from the production process |
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NSK solution: Bearings of Water Tough (WTF) steel |
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More than 3X longer bearing life – reducing bearing consumption, downtime and maintenance costs |
Value Proposals
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Analysis of the bearings, grease, structure and roll design |
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NSK WTF steel bearings – designed for extreme operating conditions including solid and liquid contamination – were recommended |
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Technical support including on-site engineering consultancy and lab-based bearing analysis |
Product Features
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Advanced WTF (Water-Tough) material composition containing appropriate levels of chrome and molybdenum for increased hardness |
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Innovative and patented heat treatment technology to optimize retained austenite and formation of finer carbide and carbonitride particles |
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Significantly outperforms standard bearing steel in seizure resistance, rate of wear and service life |
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Available for four-row cylindrical and four-row taper roller bearings |
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Bearing life is 3 times longer than that of conventional bearing |
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Grain boundaries have been strengthened to help prevent the propagation of cracks |

Four-Row WTF
(Water Tough)
Tapered Roller Bearing
(Water Tough)
Tapered Roller Bearing
Cost-Savings Breakdown
Before | Cost | NSK Solution | Cost | |||
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Bearing life of the previous bearings: 4 months, Lost production: $1,071/hr downtime X number of replacements X 4 unexpected downtimes per year | $47,147 | Bearing life of the new bearings: 12 months Lost production: $1,071/hr downtime X number of replacements X 1 unexpected downtime per year | $18,859 | ||
Total Costs | $47,147 | Total Costs | $18,859 |
Before | Cost | |
---|---|---|
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Bearing life of the previous bearings: 4 months, Lost production: $1,071/hr downtime X number of replacements X 4 unexpected downtimes per year | $47,147 |
Total Costs | $47,147 |
NSK Solution | Cost | |
---|---|---|
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Bearing life of the new bearings: 12 months Lost production: $1,071/hr downtime X number of replacements X 1 unexpected downtime per year |
$18,859 |
Total Costs | $18,859 |
Your Partner for Machine Optimization
Our AIP Added Value Program is based around a simple proposition: ‘improvement pays’. By working with you throughout the AIP Value Cycle, we will help you achieve improvements in machine reliability, productivity and performance, all of which carry a tangible and measurable cost benefit – and we have the tools to prove it! That’s what we mean by improvement pays.
