FEATURE
FERROFLUID BEARING SPINDLE
BALL-BEARING SPINDLE
Repeatable runout, um
0.125 to 1.25
1.25 to 5.0
Nonrepeatable runout, um
< 0.05
0.25 to 1.25
Contamination
Self-contained exclusion seal
Needs exclusion seal
Audible noise
Low
High
Bearing shock
Critically
None
Damping
No brinelling
Brinelling
Power consumption (bearing alone), W
2 to 8
2 to 5