SKF cylindrical roller bearings designation system, The designations of most SKF rolling bearings follow a system that may consist of a basic designation with or without one or more prefixes and/or suffixes (SKF bearing nomenclature)
Prefixes
- L: Separate inner or outer ring of a separable bearing
- R: Inner or outer ring with roller and cage assembly of a separable bearing
Basic designation
- CRL: Inch bearing
- CRM: Inch bearing
- HJ: Angle ring
Suffixes - Internal design
- A: Deviating or modified internal design
- EC: Optimized internal design incorporating more and/or larger rollers and with modified roller end / flange contact
Suffixes - External design (seals, snap ring groove etc.)
- K: Tapered bore, taper 1:12
- N: Snap ring groove in the outer ring
- NR: Snap ring groove in the outer ring, with appropriate snap ring
- N1: One locating slot (notch) in one outer ring side face
- N2: Two locating slots (notches) in one outer ring side face, 180° apart
Suffixes - Cage design
- FR: Pin-type steel cage, pierced rollers
- J: Stamped steel cage, roller centred
- L: Machined light alloy cage, riveted, roller centred
- LA: Machined light alloy cage, outer ring centred
- LB: Machined light alloy cage, inner ring centred
- LL: Machined light alloy cage, window-type, inner or outer ring centred (depending on bearing design)
- M: Machined brass cage, riveted, roller centred
- MA(S): Machined brass cage, outer ring centred. The S indicates a lubrication groove in the guiding surface
- MB: Machined brass cage, inner ring centred
- ML: Machined brass cage, window-type, inner or outer ring centred (depending on bearing design)
- MP: Machined brass cage, window-type, inner or outer ring centred (depending on bearing size)
- MR: Machined brass cage, window-type, roller centred
- P: Glass fibre reinforced PA66 cage, roller centred
- PA: Glass fibre reinforced PA66 cage, outer ring centred
- PH: Glass fibre reinforced PEEK cage, roller centred
- PHA: Glass fibre reinforced PEEK cage, outer ring centred
Suffixes - Materials, heat treatment
- HA1: Case-hardened inner and outer rings
- HA2: Case-hardened outer ring
- HA3: Case-hardened inner ring
- HB1: Bainite-hardened inner and outer rings
- HB3: Bainite-hardened inner ring
- HN1: Inner and outer rings with special surface heat treatment
Suffixes - Accuracy, clearance, preload, quiet running
CN: Normal radial internal clearance; only used together with an additional letter that identifies a reduced or displaced clearance range
- H = Reduced clearance range corresponding to the upper half of the actual clearance range
- L = Reduced clearance range corresponding to the lower half of the actual clearance range
- M = Reduced clearance range corresponding to the middle half of the actual clearance range
The above letters are also used together with the clearance classes C2, C3, C4 and C5, e.g. C2H
C2: Radial internal clearance smaller than Normal
C3: Radial internal clearance greater than Normal
C4: Radial internal clearance greater than C3
C5: Radial internal clearance greater than C4
Suffixes - Bearing sets, matched bearings
- DR: Set of two matched bearings
- TR: Set of three matched bearings
- QR: Set of four matched bearings
Suffixes - Stabilization
- S1: Bearing rings heat stabilized for operating temperatures ≤ 200 °C (390 °F)
- S2: Bearing rings heat stabilized for operating temperatures ≤ 250 °C (480 °F)
Suffixes - Lubrication
W33: Annular groove and three lubrication holes in the outer ring
Suffixes - Other variants
- PEX: SKF Explorer bearing, used only when same-sized conventional and SKF Explorer bearings are available
- VA301: Bearing for railway vehicle traction motors
- VA305: VA301 + special inspection routines
- VA350: Bearing for railway axleboxes
- VA380: Bearing for railway axleboxes in accordance with EN 12080:2011, class 1
- VA3091: VA301 + external surfaces of the outer ring are coated with aluminium oxide
- VC025: Bearing with special wear-resistant raceways for applications in heavily contaminated environments
- VE901: Modified internal design
- VQ015: Inner ring with crowned raceway for increased permissible misalignment
