Koyo
FOR REFERENCE ONLY
  • Tapered roller bearings
  • Single-row
  • Inch series


Bearing No. 3984/25

Specification data (main dimensions, etc.)

d(mm)66.675
D(mm)112.712
T(mm)30.162
B(mm)30.048
C(mm)23.812
r(min.)(mm)3.6
r1(min.)(mm)0.8
Basic load ratings : Cr(kN)139
Basic load ratings : C0r(kN)164
Fatigue load limit : Cu(kN)25.1
Limiting speeds(Grease lub.)(min-1)3400
Limiting speeds(Oil lub.)(min-1)4500
Load center spread : a(mm)25.9
Constant :e0.40
Axial load factors : Y11.49
Axial load factors : Y00.82

Mounting dimensions,weight (reference)

da(mm)80.0 mm
db(mm)74.0 mm
Da(mm)101.0 mm
Db(mm)106.0 mm
ra(max.)(mm)3.6 mm
rb(max.)(mm)0.8 mm
Mass(Refer.)(kg)1.154 kg
JTEKT

2026/07/30