Explanation of TIMKEN Bearing Prefixes

Please see the table below for TIMKEN bearing part number prefixes

PREFIX  CONE OR CUP EXPLANATION
A Cone and Cup Standard basic series part number
CN Cup Neoprene cushioned  cup
EE Cone Large and small ribs-close guided rollers. (Non-interchangeable with other cones identified with the same basic part numbers).
EH Cone and Cup Extra heavy series
EL Cone and Cup Extra light series
EX Cone and Cup Experimental
FL Cone and Cup “Free lateral” series, no large or small ribs
FX Cone and Cup Factory identification number only
H Cone and Cup Heavy series. (Non- interchangeable with other cups and cones identified with the same basic part numbers.)
HH Cone and Cup Heavy-Heavy series. (Non-interchangeable with other cones and cups identified with the same basic part number.)
HM Cone and Cup Heavy-Medium series. (Non- interchangeable with other cups and cones identified with the same basic part numbers).
J Cone and Cup Used alone or with other prefix letters to indicate metric bore and/or O/D
J,JC,JD,JE,JF,JG,JN,JP,JR,JS,JT,JU,JW. Cone and Cup Metric Series
JRM Cone and Cup Metric series, UNIPAC bearing
K Cup Double cup with heavy section. May have unusual feature such as flange. (Non-interchangeable with basic part number).
L Cone and Cup Light series. (Non-interchangeable with other cones and cups identified with same basic part numbers).
LL Cone and Cup Light-Light series
LM Cone and Cup Light-Medium series
M Cone and Cup Medium series
N Cone Bock or Gilliam type bearings
NA Cone Two cones mated with double cup to form double row non-adjustable bearing. (Non-interchangeable with other cones having the same basic part numbers which may vary in bore, O.D. and width dimensions.)
NP Cone and Cup Used with random numbers for product differentiation.
R Cone and Cup Gilliam replacement series.(Non-interchangeable with other cones and cups identified with same basic part numbers.)
RC Cone and Cup Special ribbed cup bearing.
T Race Thrust bearing assemblies
T Cup Double cup with heavy section. May have unusual feature such as flange, tapered O.D. etc.
TC Race Thrust bearing assembly
U Cone and Cup Basic series part number, unitized, self – contained.
V Cone and Cup Special close stand
X Cone ISO Class part number
XAA Cone ISO Class single cone.(Non-interchangeable with bearings having the same basic part number.)
XAB Cone ISO Class single cone. (Non-interchangeable with bearings having the same basic part number.)
XC Cone and Cup Limited production bearings to which standard series part numbers have not been assigned
XGA Cone ISO Class single cone. (Non- interchangeable with bearings having the same basic part number.)
XGB Cone ISO Class single cone. (Non-interchangeable with bearings having the same basic part number.)
XR Crossed roller bearing series
Y Cup ISO Class part number
YKB Cup ISO Class single cup. (Non-interchangeable with bearings having the same basic part number.)
YSA Cup ISO Class single cup. (Non-interchangeable with bearings having the same basic part numbers.)