Page 694 - Rollingbearings

8 Tapered roller bearings

Designation system
x y Group 1 Group 2 Group 3 /

Preixes
J Metric bearing following the ABMA designation system (ANSI/ABMA Std. 19.2)
T Metric bearing in accordance with ISO 355

Basic designation
Refer to Bearing designations, page 691 or drawing number identiication.
BT2- Drawing number preixes that may precede a four- or six-digit drawing number
BT2B

Sufixes
Group 1: Internal design
A, C, D Deviating or modiied internal design, combinations are possible
B Steep contact angle

Group 2: External design (seals, grooves, etc)
E SKF Explorer bearing (only for double row bearings)
G Helical groove in the inner ring bore (only for double row bearings)
R Flanged outer ring
T.. A number immediately following the T identiies the total width of matched bearings,
arranged back-to-back or in tandem.
X Boundary dimensions changed to conform to ISO

Group 3: Cage design
TN9 Glass ibre reinforced PA66 cage, roller centred
TNH Glass ibre reinforced PEEK cage, roller centred
8 Group 4.1: Materials, heat treatment

HA1 Case-hardened inner and outer rings
HA2 Case-hardened outer ring
HA3 Case-hardened inner ring
HA4 Case-hardened inner and outer rings and rollers
HA5 Case-hardened rollers
HA6 Case-hardened outer ring(s) and rollers
HA7 Case-hardened inner ring(s) and rollers
HB1 Bainite-hardened inner and outer rings
HB2 Bainite-hardened outer ring(s)
HN3 Inner ring with special surface heat treatment
L4B Bearing rings and rollers with special surface coating

Group 4.2: Accuracy, clearance, preload, quiet running
/1 Deviating width tolerances of cups and cones for inch bearings (table 4, page 678)
/-1
to
/-3
/4
C... Axial internal clearance (only for double row bearings)
The three- or four-digit number immediately following the C is the mean axial internal
clearance in µm.
CL0 Geometrical tolerances to ABMA tolerance class 0 (inch bearing)
CL00 Geometrical tolerances to ABMA tolerance class 00 (inch bearing)
P5 Geometrical tolerances to P5 tolerance class
U.. U combined with a one- or two-digit number identiies tighter total width tolerance, e.g.:
U2 → +5/0 µm
U4 → +10/0 µm
W Modiied ring width tolerance to +5/0 µm

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