Mood, Industries, 1600x230


A customer in the US was experiencing premature bearing failures in a collet closer application. The target was a lifetime of 15000 hrs minimum, but the bearing failed after only 100 hrs. This led to significant bearing replacements required on a weekly basis, leading to high cost and lost production.

NSK engineers reviewed the application and proposed to use a pair of Angular Contact Ball Bearings on the front and the back side of the spindle instead of the existing double row bearing which could not support the axial load. After the implementation, failures were eliminated and significant cost savings were realised.


Machine Tools, Milling Machine
  • Collet Closer
ACBB, Sealed, Peek Cage, 2Comp
  • NSKHPS Precision Angular Contact Ball Bearings

Key Facts

  • Collet closer
  • Premature bearing failure
  • NSK solution: a pair of Super Precision Angular Contact Ball Bearings at the front and the back side of the spindle providing the capability  for supporting the high thrust loads and resulted in cooler running temparatures and longer bearing life
  • Significant cost saving realised

Value Proposals

  • NSK experts performed an Application Review
  • The review showed that the used bearing was not adequate for the application
  • NSK recommended to use a pair of Super Precision ACBB at the front and the back side of the spindle
  • The customer benefitted from a significant increase of the bearing life and the avoidance of loss of production

Product Features

  • High speed capacity for accurate operation 
  • 25° contact angle for good axial load capacity 
  • P4Y precision class running performance
Cost Saving Breakdown
Before Cost p.a. NSK Solution Cost p.a.
Bearing Costs: Bearing replacement cost: once per week = 52 sets 5 200 € Bearing Costs: Bearing replacement cost 6 600 €
Engineering Costs: Maintenance cost (to replace spindle): 60€/hr x 3 hrs x 52 weeks 9 360 € Engineering Costs
Costs of lost production: Downtime cost: 1000€/hr x 3 hrs x 52 weeks 156 000 € Costs of lost production
Engineering Costs: Engineering support 1 000 € Engineering Costs
Total Costs € 171 560 € 6 600