NSK Case Study


Hot Strip Mill

Cost Savings: $165,088

A large steel manufacturer wanted to increase replacement intervals of Four-Row Tapered Roller Bearings used in the hot strip mill. Due to severe operating conditions, standard bearings provided only 1,400 hours of operation. The key target was to decrease spend on bearing replacement and maintenance. NSK inspected the bearing units along with the operating conditions. As a result new Super-TF Four-Row Tapered Roller Bearings with modified internal design and contact angle were delivered for testing. With the suggested solution, bearing lifetime was increased to 2,200 hours.

Key Facts

Four-Row Tapered Roller Bearings running only 1,400 hours before needing replacement
Failures were causing frequent line stoppages
NSK Solution: Super-TF bearings with modified internal design
Increased bearing life – reduced bearing consumption, reduced downtime, reduced maintenance costs

Finishing Section of Hot Strip Mill

Value Proposals

NSK engineers inspected the machine and operating conditions
The Analysis showed that the existing bearing solution was not adequate for the application
Due to the severe operating conditions, NSK recommended additional modification of the bearings internal design along with a suggested contact angle change
Training was provided regarding root cause failure to prevent further issues
The customer received increased bearing life and reduction in maintenance costs, bearing consumption and downtime

Product Features

Advanced Super-TF material composition containing appropriate levels of chrome and molybdenum for increased hardness
Innovative and patented heat treatment technology to optimize retained austenite and formation of finer carbide and carbonitride particles
Significantly outperforms standard bearing steel in seizure resistance, rate of wear and service life
Reduced non-metallic inclusions on raceway surface inhibiting the generation of surface cracks
NSK Super-TF Four-Row
Tapered Roller Bearing

Cost-Savings Breakdown

  Before Cost NSK Solution Cost  
  Bearing replacement $463,105 Bearing replacement $308,737  
  Additional maintenance incurred versus NSK solution $10,720      
  Total Costs $473,825 Total Costs $308,737  
Before Cost
Bearing replacement $463,105
Additional maintenance incurred versus NSK solution $10,720
Total Costs $473,825
NSK Solution Cost
Bearing replacement
Total Costs $308,737

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.