Suffixes D - F

D
  1. Deviating or modified internal design with same boundary dimensions; as a rule the significance of the letter is bound to the particular bearing series

    Examples:
    • 3310 D Double row angular contact ball bearing with a two-piece inner ring
    • K 40×45×17 D Split needle roller and cage assembly (radial)
  2. Inner ring with two roller and cage assemblies (double cone) or outer ring with two raceways (double cup) of double row tapered roller bearing to ABMA standard (normally inch-size)
DBTwo single row deep groove ball bearings (1), single row angular contact ball bearings (2) or single row tapered roller bearings matched for mounting in a back-to-back arrangement. The letter(s) following the DB indicate the magnitude of the axial internal clearance or preload in the bearing pair before mounting.
A Light preload (2)
B Moderate preload (2)
C Heavy preload (2)
CA Axial internal clearance smaller than Normal (CB) (1, 2)
CB Normal axial internal clearance (1, 2)
CC Axial internal clearance larger than Normal (CB) (1, 2)
C Special axial internal clearance in µm
GA Light preload (1)
GB Moderate preload (1)
G Special preload in daN
DFTwo single row deep groove ball bearings, single row angular contact ball bearings or single row tapered roller bearings matched for mounting in a face-to-face arrangement; the letter(s) following the DF are explained under DB
DGTwo single row angular contact ball bearings for universal pairing, i.e. paired for mounting in a back-to-back, face-to-face or tandem arrangement; supplementary designations for axial internal clearance and preload are explained under DB
DHSingle direction thrust bearing with two housing washers
DRTwo single row deep groove ball bearings or cylindrical roller bearings paired to achieve even radial load distribution
DS
  1. Single direction thrust bearing with two shaft washers
  2. Split radial needle roller and cage assembly
DTTwo single row deep groove ball bearings, single row angular contact ball bearings or single row tapered roller bearings matched for mounting in a tandem arrangement; for paired tapered roller bearings the design and arrangement of the intermediate rings between the inner and/or outer rings are identified by a two-figure number which follows immediately after DT
D8Deep groove ball bearing of open design, also available as standard with shields or seals, but without seal recesses in the outer ring
EDeviating or modified internal design with same boundary dimensions; as a rule the significance of the letter is bound to the particular bearing series; usually indicates reinforced rolling element complement

Example:
  • Single row angular contact ball bearing with a 40° contact angle and optimized internal design
ECSingle row cylindrical roller bearing with an optimized internal design and with modified roller end/flange contact
ECASpherical roller bearing of CA design but with reinforced rolling element complement
ECACSpherical roller bearing of CAC design but with reinforced rolling element complement
Exx(x)E combined with a two or three-figure number identifies variants of the standard design which cannot be identified by generally applicable suffixes
FMachined steel or special cast iron cage, rolling element centred; different designs or material grades are identified by a figure following the F, e.g. F1
FAMachined steel or special cast iron cage; outer ring centred
FBMachined steel or special cast iron cage; inner ring centred
2FY-bearing with plain flinger at both sides
SKF logo