Rolling bearing suffixes: The lexicon

Introduction

Rolling bearings are precision components and small details often determine their suitability for a particular application. These details are often described by cryptic-looking combinations of letters and numbers at the end of the bearing designation, the so-called suffixes (NSZ). This glossary is intended to shed some light on the most common suffixes.

Please note: This list is based on the information provided, makes no claim to completeness and serves as a guide. The meaning of a suffix may vary depending on the bearing series or manufacturer.

1. internal design & execution

These signs indicate changes or optimizations inside the bearing, often with effects on load carrying capacity or running properties.

• A:  Modified internal design with the same main dimensions. The exact meaning often depends on the bearing series (e.g. increased load carrying capacity for deep groove ball bearings, polyamide cage for angular contact ball bearings).
• Axx(x): Variants of the standard version that cannot be marked by usual suffix characters (xx or xxx is a two- or three-digit number).
• B: Modified internal construction, often dependent on bearing series (e.g., increased contact angle in tapered roller bearings, 40° angle in angular contact ball bearings, standard in spherical roller bearings).
• B1: Modified internal construction with the same main dimensions.
• Bxx(x): Variants of the standard version that cannot be marked by usual suffix characters (xx or xxx is a two- or three-digit number).
• C: Modified internal construction (e.g., in tapered roller bearings).
• C12: Index of Internal Design for Tapered Roller Bearings.
• CV: Modified internal construction, full rolling version (without cage).
• D: Modified interior construction.
• E: Modified internal construction, usually with increased load capacity or optimized roller set.
• EA: Self-aligning roller bearing with increased load capacity and steel sheet cage.
• EC: Optimized internal design in cylindrical roller bearings (more/larger rollers, modified roller-raceway contact).
• ECA: Spherical roller bearings according to CA design, but with an optimized rolling element set for higher load capacity.
• ECAC: Spherical roller bearings according to CAC design, but with an optimized rolling element set for higher load capacity.
• Exx(x): Variants of the standard version that cannot be identified by standard suffixes (xx or xxx is a two- or three-digit number).
• Q: Optimized internal geometry and surface quality (for tapered roller bearings).
• ST: Modified internal structure (low torque).
• STVn: Modified internal structure (n = 1, 2, 3...) (low torque).
• U: Reinforced design for tapered roller bearings.
• V: Full rolling bearing (without cage, increased number of rollers).
• V: Modified internal geometry in spherical roller bearings.
• Vxx(x): Indicates variants that cannot be described with standard suffixes (xx(x) is a three- or four-digit number).

2. Tolerance Classes & Precision

These symbols define the dimensional, geometric, and running accuracy of the bearing.

• ABEC-1: Tolerance class 1 according to ABMA, corresponds to P0 (DIN 620) / Normal class (ISO 492).
• ABEC-3: Tolerance class 3 according to ABMA, corresponds to P6 (DIN 620) / Class 6 (ISO 492).
• ABEC-5: Tolerance class 5 according to ABMA, corresponds to P5 (DIN 620) / Class 5 (ISO 492).
• ABEC-7:Tolerance class 7 according to ABMA, corresponds to P4 (DIN 620) / Class 4 (ISO 492).
• ABEC-9: Tolerance class 9 according to ABMA, corresponds to P2 (DIN 620) / Class 2 (ISO 492).
• B20: Narrowed Width Tolerance.
• C02: Particularly tight tolerance of the running accuracy of the inner ring.
• C04: Particularly tight tolerance of the running accuracy of the outer ring.
• C08: Combination of C02 and C04.
• C10: Tight tolerance for hole and outer diameter.
• CL0: Inch tapered roller bearings according to Class 0 (ANSI-ABMA Standard 19.2:1994).
• CL00: Inch tapered roller bearings according to Class 00 (ANSI-ABMA Standard 19.2:1994).
• CL3: Inch tapered roller bearings according to Class 3 (ANSI-ABMA Standard 19.2:1994).
• CL7C: Cylindrical roller bearings with special friction behavior and increased running accuracy.
• CLN: Cylindrical roller bearings with tolerances according to ISO tolerance class 6X.
• P4: Dimensional and running accuracy according to ISO tolerance class 4 (very high accuracy, more accurate than P5).
• P4A: Dimensional and running accuracy according to ISO tolerance class 2 or ABMA ABEC 9.
• P5: Dimensional and running accuracy according to ISO tolerance class 5 (particularly high accuracy, more precise than P6)).
• P6: Dimensional and running accuracy according to ISO tolerance class 6 (increased accuracy, more precise than normal tolerance P0).
• PA9 / PA9A: Dimensional and running accuracy according to ABMA tolerance class ABEC 9 (better than P4).
• PA9B: Like PA9, but running accuracy better than ABMA ABEC 9.
• PK: Precision class K for tapered rollers, series J.
• PM: Special precision bearings for electric motors.
• PXn: Special precision with development index n.
• SP: Special accuracy class for spindle bearings (dimensional accuracy approx. P4, running accuracy approx. P4)).
• UP: Ultra-Precision (highest accuracy class for spindle bearings).
• VQ424: Running accuracy better than C08.

3. bearing clearance

The bearing clearance is the total displacement of one bearing ring relative to the other (radial or axial).

• C0 / CN: Normal bearing clearance (is often not explicitly stated).
• C1: bearing clearance smaller than C2.
• C2: bearing clearance smaller than Normal (CN).
• C3: bearing clearance bigger than Normal (CN).
• C4: bearing clearance bigger than C3.
• C5: bearing clearance bigger than C4.
• C9: High precision play (unclear whether smaller or larger than normal, context required)).
• C083: Tolerances C02 + C04 combined with bearing clearance C3.
• P43: Precision P4 combined with bearing clearance C3.
• P52: Precision P5 combined with bearing clearance C2.
• P62: Precision P6 combined with bearing clearance C2.
• P63: Precision P6 combined with bearing clearance C3.
• P63E: Precision P6 and Air C3 / DIN Standard Electric Motors.
• CMxx: Average clearance in micrometers (µm) for ball bearings (diameter 10-50mm). e.g.. CM09 = 5-13 µm, CM25 = 21-29 µm.
• CSxx: Average bearing clearance in micrometers (µm).
• CNF: Reduced and shifted air range (upper quarter of the actual and lower quarter of the next higher air class)).
• CNH: Reduced air range according to the upper range of normal air.
• CNL: Reduced air range according to the lower range of normal air.
• CNM: Reduced air area corresponding to the two middle quarters of the air area.
• CNP: Upper half of the normal air range and lower half of the C3 air range.
• CNR: Reduced air area according to "paired rings" per ISO 5753:1981.
• CNS / CNL: Clearance for precision miniature bearings.
• CxNA: Constricted air areas (medium air, however, identical), grouped rings.
• CA (in angular contact ball bearings): Low axial clearance before installation.
• CB (in angular contact ball bearings): Normal axial clearance before installation.
• CC (in angular contact ball bearings): Larger axial clearance before installation.
• CB1 / CB2: Special axial play in paired or double-row angular contact ball bearings.
• CC1 / CC2: Special axial play in paired spherical roller or angular contact ball bearings .
• SPC2: Special accuracy SP with reduced bearing clearanceC2.
• SPCN: Special accuracy SP with normal bearing clearance CN.

4. Angle of contact

Relevant for angular contact ball bearings and tapered roller bearings; determines the axial load capacity.

• AC: Single-row angular contact ball bearing, contact angle 25°.
• ACD: Like AC, but with optimized internal construction.
• AD: Contact angle 25°.
• B (in angular contact ball bearings): Angle of contact 40° (single-row) or 32° (double-row).
• B (in tapered roller bearings): Increased contact angle (e.g., 20° or greater than standard).
• BE: Single-row angular contact ball bearing, contact angle 40°, optimized internal design.
• BEJ / BEM / BEP / BEY: Variants of BE with different cages (steel sheet, solid brass, polyamide, brass sheet)).
• C (in angular contact ball bearings): contact angle 15°.
• C (in tapered roller bearings): increased contact angle.
• CD: single-row angular contact ball bearings, contact angle 15°, optimized Interior construction.
• D (in tapered roller bearing): increased contact angle.

5. Cage types & materials

The cage keeps the rolling elements spaced apart. Material and design affect speed, temperature, and durability.

• A (in certain series): Polyamide Cage.
• B (in spherical roller bearings): Modified, roller-guided double-tooth cage made of brass.
• BEJ: Sheet steel cage, ball-guided (with 40° angular contact ball bearings).​
• BEM: Solid brass cage (with 40° angular contact ball bearings).
• BEP: Injection-molded cage made of glass fiber-reinforced polyamide 66 (with 40° angular contact ball bearings).
• BEY: Sheet brass cage, ball-guided (with 40° angular contact ball bearings).
• ECJ: Optimized internal construction, with sheet steel cage.
• ECM: Roller-guided with brass cage.
• ECP: Optimized internal construction, with plastic cage (standard version).
• EM: Spherical roller bearing with increased load carrying capacity and solid cage.
• F: Solid cage made of steel or special cast iron, guided by rolling elements.
• F1: Solid steel cage.
• F3: Solid cage made from machined steel.
• FA: Outer ring guided double tooth cage made of steel.
• FB: Inner ring guided double tooth cage made of steel. (Note: The original said “Facebook”, this is most likely a typo for FB).
• FP: Steel window cage, rolling element guided.
• G1: Solid brass cage.
• G14: Polyamide cage.
• G15: Glass fiber reinforced polyamide cage.
• H: Snap-on cage made of sheet steel, pressed and hardened.
• H1: Like H.
• J: Sheet steel cage, pressed, roller-guided, unhardened (only specified if not standard).
• J2: SKF Tapered roller bearing: sheet steel cage in design variant 2.
• JH: Sheet steel snap-in cage, rolling element guided.
• JHA:  Sheet steel cage, pressed and hardened, external ring guide.
• JN: Sheet steel rivet cage, rolling element guided.
• JP / JP1: Sheet steel window cage, rolling element guided.
• JPA: Sheet steel window cage, guide on outer ring.
• JPB: Sheet steel window cage, guide on inner ring.
• JR:  Cage made of two flat sheet steel disks, riveted, unhardened.
• JW: Sheet steel cage, unhardened and welded.
• KTN9: Combination of K (tapered bore) and TN9 (polyamide cage).
• L: Solid cage made of light metal (various versions L1, etc.).
• L1: Riveted solid brass cage (can also stand for housing features).
• LA: Riveted solid light metal cage with outer ring guide.
• LB: Riveted light metal solid cage with inner ring guide.
• LP:  Solid window cage made of light metal, butt-jointed or milled pockets, internally or externally ring-guided.
• LPA: Like LP, but outer ring guided.
• LPB: Like LP, but inner ring guided.
• LPS: Like LP, but with lubrication grooves in the guide surfaces.
• M: Solid brass cage, rolling element guided.
• M1: Solid brass cage, rolling element guided. (Bars riveted).
• M1A / M1B: Like M1, but outer ring- / inner ring guided.
• M3: Solid brass cage Modified version, rolling element guided.
• M3A / M3B: Like M3, but outer ring- / inner ring guided.
• MA: Solid brass cage, guide on outer ring.
• MAS: Like MA, with Lubrication grooves.
• MB: Solid brass cage, guide on inner ring.
• MBS: Like MB, with Lubrication grooves
• ML: Undivided window solid brass cage with milled, punched or milled pockets, inner or outer ring guided.
• MP / MP1: Solid brass window cage, rolling element guided.
• MPA / MPB: Like MP, but outer ring- / inner ring guided.
• MPS: Like MP, but with lubrication grooves in the guide surfaces.
• MR: Solid, one-piece brass window cage with rolling element guide.
• P: Injection-molded cage made of glass fiber-reinforced Polyamide 66, rolling element guided..
• PH: Injection-molded cage made of glass fiber-reinforced PEEK, rolling element guided..
• PHAS: Like PH, but outer ring guided (with lubrication grooves if necessary).
• SE1: Sintered iron solid window cage, rolling element guided.
• SE1A / SE1B: Like SE1, but outer ring- / inner ring guided.
• T: Window cage made of hard fabric (fabric-reinforced phenolic resin), guided by rolling elements.
• T1: Fabric cage with Bakelite coating.
• T2: Cage made of plastic, nylon or Teflon.
• T2X: Special polyamide cage (4.6) for sealed ball bearings or cylindrical roller bearings.
• T6: PEEK-cage for NN-Bearing.
• TA: Hard fabric solid cage, guide on outer ring.
• TB: Hard fabric solid cage, guide on inner ring.
• TH: Snap-on cage made of hard fabric, rolling element guided.
• THA / THB: Like TH, but outer ring / inner ring guided.
• TN / TNS: One- or two-piece cage made of polyamide 66, guided by rolling elements.
• TN9: Like TN, but made of glass fiber-reinforced polyamide 66.
• TNH: Injection-molded snap-in cage made of fiber-reinforced PEEK, guided by rolling elements.
• TNHA: Like TNH, but outer ring guided.
• TNP: Polyamide window cage, rolling element guided.
• TPA / TPB: Hard fabric window cage, outer ring / inner ring guided.
• TV: Polyamide solid cage, rolling element guided.
• TVA / TVB: Like TV, but outer ring / inner ring guided.
• TVH: Polyamide snap-in cage, rolling element guided.
• TVHB: Like TVH, but inner ring guided.
• TVP / TVP2 / TVP3: Polyamide window cage, rolling element guided.
• TVPB / TVPB1: Like TVP, but inner ring guided.
• VG114: Surface-hardened window cage made of sheet steel.
• Y: Cage made of sheet brass, guided by rolling elements.
• YPB: Sheet brass window cage, guide on inner ring.

6. Seals & Cover Discs

Protect the bearing from contamination and keep the lubricant in the bearing.

• 2C: Double-sided slinger plate sealed housing bearing.
• CC: Closed stainless steel closure for housing bearing.
• CO: Open stainless steel lock for housing bearing.
• CS: Single-sided, sheet steel-reinforced sealing washer made of NBR (acrylonitrile butadiene rubber)..
• 2CS: CS seals on both sides.
• CS2: One-sided, sheet steel-reinforced sealing washer made of FKM (fluororubber).
• 2CS2: CS2 seals on both sides.
• CS5: Single-sided, sheet steel-reinforced sealing washer made of H-NBR (hydrogenated acrylonitrile butadiene rubber).
• 2CS5: CS5 seals on both sides.
• DD / DDU: Lip seals on both sides (often NBR).
• DS: Double lip seal for SNC bearing housings.
• EEE: Sealing on both sides.
• 2F: Standard contact seals on both sides with additional upstream flinger plate.
• FS: Felt strip seal for SNC bearing housings.
• FT150: High temperature resistant sealing washers on both sides (-150°C).
• KLL:  Double-sided labyrinth seal (L-seal) for housing bearings.
• KRR: Lip seal (R seal) on both sides for housing bearings.
• KTT: 3-lip seal (T seal) on both sides for housing bearings.
• L3: Triple lip seal for bearing inserts.
• LA: Labyrinth seal for SNC bearing housings.
• LB: Non-contact nitrile rubber seal (-25 to +120°C).
• LBA: Non-contact polyacrylic rubber seal (-10 to +150°C).
• LBA1: Non-contact fluoroelastomer gasket (-30 to +200°C).
• LBA2: Non-contact silicone gasket (-100 to +200°C).
• LFS: Low-friction seals on both sides (axial and radial sealing lip, non-contacting on the inner ring).
• LH: Contacting nitrile seal, low torque (-25 to +120°C).
• LHA / LHA1 / LHA2 / LHA4 / LHAX12: Variants of LH made of other materials (polyacrylic, fluoroelastomer, silicone, high nitrile) for different temperature ranges.
• LLB / LLBA / LLBA1 / LLBA2: Non-contact seals on both sides (materials like LB/LBA/LBA1/LBA2).
• LLH / LLHA / LLHA1 / LLHA2 / LLHA4 / LLHAX12: Contact seals on both sides with low torque (materials such as LH/LHA etc.).
• LLJ: Bearings with double lip seals and low torque.
• LLS: Bearing with triple lip seal and high torque.
• LLU: Contacting nitrile rubber seal on both sides (-20 to +120°C).
• LLUA / LLUA1 / LLUA2 / LLUA4 / LLUAX12: Variants of LLU made of other materials (polyacrylic, fluoroelastomer, silicone, high nitrile) for different temperature ranges.
• LS: Single-sided contact seal made of NBR or polyurethane (AU), with or without sheet steel reinforcement.
• 2LS: Contact seals on both sides made of polyurethane (AU).
• 2LS8: Contact seals on both sides made of synthetic rubber with sheet steel reinforcement.
• LU: Contacting nitrile seal (-20 to +120°C).
• LUA / LUA1 / LUA2 / LUA4 / LUAX12: Variants of LU made of other materials (polyacrylic, fluoroelastomer, silicone, high nitrile) for different temperature ranges.
• LX: Gasket with special sealing.
• NPP: Lip seal on both sides (P seal) for housing bearings (old designation for 2RSR).
• P: Single-sided seal (for yoke and stud type track rollers).
• PP: Contact seals on both sides made of acrylonitrile-butadiene (for yoke type track rollers, cam followers and track rollers). / Axial sliding washer on both sides made of plastic with molded-on sealing lip (three-stage sealing).
• PPA: Axial plain washers on both sides made of polyamide 66 (for support rollers, cam followers and track rollers), improved track profile.
• RF: Rubber flinger washer on one side (sheet steel with vulcanized sealing lip) for Y-bearings (radial insert ball bearings).
• 2RF: Standard contact seal on both sides with additional rubber flinger washer.
• RS: Single-sided contact seal made of NBR, with or without sheet steel reinforcement.
• 2RS: RS seal on both sides. / For SKF Y-bearings: Standard seals with flinger washer on both sides.
• RS1: Single-sided, sheet steel-reinforced contact seal made of NBR.
• 2RS1: RS1 seal on both sides.
• RS1Z: RS1 seal on one side, Z-cover washer on the other side.
• RS2: Single-sided, sheet steel-reinforced contact seal made of FKM (fluororubber).
• 2RS2: RS2 seal on both sides.
• RSH: Single-sided, sheet steel-reinforced contact seal made of NBR.
• 2RSH: RSH seal on both sides.
• RSL: Single-sided, sheet steel-reinforced, low-friction contact seal made of NBR.
• 2RSL: RSL seal on both sides.
• RSR: Single-sided plastic lip seal (old designation NPP(U)).
• 2RSR: RSR seal on both sides (old designation NPP(U)).
• RZ: Single-sided, sheet steel-reinforced, low-friction seal made of NBR.
• 2RZ: RZ seal on both sides.
• SV: V-ring seal complete for SNC bearing housings.
• TA: Taconite seal for SNC bearing housings.
• VV: Non-contact plastic seal on both sides, similar to 2RSL.
• VP076: Pressed sheet steel covers on each bearing side.
• VIT: Shaft seals based on fluororubber (FPM/FKM), more temperature-resistant than standard NBR.
• Z: Single-sided cover plate made of sheet steel / flange bearing with rubber seal type Z.
• Z1: Combined needle roller bearings with cover / protective cover made of stainless steel.
• Z2: Single-sided sheet steel cover washer. / Flange bearing with felt strip seal. ZA:
• ZA: Removable protective cover.
• ZZ / 2Z: Cover plates on both sides made of sheet steel.
• ZZ1: Stainless steel protective cover on both sides.
• ZZA: Removable cover plates on both sides. 2ZL:
• 2ZL: Cover plate with laminar rings on both sides for support rollers.
• 2ZR: Non-abrasive sheet steel cover plate on both sides.

7. lubrication & lubrication holes/grooves

Information on factory lubrication or characteristics for relubrication.

• AS: Needle roller bearing with lubrication holes in the outer ring (number behind = number).
• ASR: Needle roller bearing with circumferential groove and lubrication hole(s) in the outer ring (number behind = number).
• AS2: Bearing outer ring with 2 lubrication holes in staggered planes (housing bearing).
• D: Lubrication holes (without groove). / High-precision angular contact ball bearings with lubrication.
• D0: Groove and lubrication holes not present (if standard).
• D1: Groove and lubrication holes in the outer ring.
• Gxx: Degree of fat filling deviating from standard (G1-G3 = less, G4-G9 = more).
• G2: Relubrication system for bearing inserts.
• GEN: EP-grease (Extreme Pressure).
• GF: Food grade grease.
• GH / GJ: Grease for high Temperatures (e.g. -20 to +130°C).
• GJN: Grease with polyurea thickener, NLGI 2, -30 to +150°C (standard filling quantity).
• GL: Grease for low Temperatures (e.g. -50 to +80°C).
• GM: Grease for middle Temperatures (e.g. -30 to +110°C).
• GW / GX: Grease for low and high Temperatures (e.g. -40 to +140°C).
• GXN: Grease with polyurea thickener, NLGI 2, -40 to +150°C (standard filling quantity)).
• HT: Grease with polyurea thickener, NLGI 2, -40 to +150°C (standard filling quantity)).
• HTxxA / HTxxF1: Filling level lower than standard.
• HTxxB / HTxxF7: Filling level hiher than standard.
• HTxxC / HTxxF9: Filling level over 70%.
• IS: Needle roller bearing with lubrication hole(s) in the inner ring (number behind = number).
• ISR: Needle roller bearing with circumferential groove and lubrication hole(s) in the inner ring (number behind = number).
• LHT: Grease filling for low and high temperatures (e.g. -40 to +140°C). Two-digit number = grease type, additional letter = different filling level.
• LHT23: Grease with lithium thickener, NLGI 2, -50 to +140°C (normal filling quantity).
• LO: Bearing without preservation, lubricated with low-viscosity oil (number behind = oil type)).
• LP03 / LP05 / LP06 / LP08: Various long-term greases (standard, high-temperature, food, needles).
• LT: Grease with lithium thickener, NLGI 2, -55 to +110°C (normal filling quantity).
• LT10: Grease with lithium thickener, NLGI 2, -50 to +90°C (normal filling quantity).
• MO: Bearing without preservation, lubricated with medium viscosity oil (number behind = oil type)).
• MT: Grease filling for medium temperatures (e.g. -30 to +110°C). Two-digit number = grease type, additional letter = different filling level.
• MT33: Grease with lithium thickener, NLGI 3, -30 to +120°C (normal filling quantity).
• MT47: Grease with lithium thickener, NLGI 2, -30 to +110°C (normal filling quantity)).
• Qx: Fat filling level in percentage ranges (QD=5-10%, QE=7.5-12.5%, ..., QT= >50%).
• S (in needle bearings INA): Lubrication hole in the outer ring/sheet metal sleeve.
• S (in Spherical roller bearings): Lubrication holes in the circumferential groove of the outer ring (similar to W33).
• SM: Needle roller bearing with grease lubrication (two-digit number = grease type).
• VT: Lubricating grease (VT143 = high pressure grease, VT378 = food grade grease).
• W: Without circumferential groove and lubrication holes in the outer ring (if standard).
• W20: Three lubrication holes in the outer ring.
• W26: Six lubrication holes in the inner ring.
• W33: Circumferential groove and three lubrication holes in the outer ring.
• W33X: Circumferential groove and six lubrication holes in the outer ring.
• W513: Six lubrication holes in the inner ring and circumferential groove + three lubrication holes in the outer ring.
• W518: Six lubrication holes in the inner ring and three lubrication holes in the outer ring.
• W64: Solid lubricant filling (solid oil).
• W77: Closed W33 lubrication holes.
• WT: Grease with polyurea thickener, NLGI 2-3, -40 to +160°C (standard filling quantity).
• Grease abbreviation (Digit + letter): e.g. 3AS (Shell Alvania S3), 5C (Chevron SRI-2), 5K (Kyodo Yushi Multemp SRL), 6K (Klüber Isoflex Super LDS 18), L417 (Kyodo Yushi E5), L453 (Klüber Asonic HQ72-102), L627 (Exxon Polyrex EM), 5S (Shell Aero Shell Grease 7).
• FD: Food grade grease.

8. materials & heat treatment

Information on special materials or surface treatments of the bearing components.

• D: Spheroidal graphite cast iron (housing).
• HA0-HA7: Components made of case-hardened steel (0=complete, 1=rings, 2=outer ring, 3=inner ring, 4=rings+rollers, 5=rollers, 6=outer ring+rollers, 7=inner ring+rollers)).
• HB0-HB7: Components bainitically hardened (numbers as for HA).
• HC0-HC7: Ceramic components (numbers as for HA).
• HE0-HE7: Vacuum-melted steel components (numbers as for HA).
• HM0-HM7: Components martensitically hardened (numbers as for HA).
• HN1: Rings with special surface hardening.
• HV: Components made of stainless, hardenable steel (numbers as for HA).
• HV (in SKF Y-Bearings): Bearing parts made of stainless steel, filled with food-grade grease.
• L4B: Bearing rings and rolling elements with special surface coating.
• L5B: Rolling elements with special surface coating.
• L5DA: NoWear bearings with coated rolling elements.
• L7DA: NoWear bearings with coated rolling elements and inner ring raceways.
• N: Cast steel (housing, e.g. P315N).
• N1: Gray cast iron GS (housing, e.g. P315N1).
• RR: Rust protection because of special Corrotect coating®.
• S0 / S1 / S2 / S3: Bearing rings heat-treated for continuous temperatures up to +150°C / +200°C / +250°C / +300°C.
• S6..: Deep groove ball bearing type 6.. made of stainless steel.
• VA: Stainless steel design (housing).
• VC025: Particularly wear-resistant, heat-treated parts for heavily soiled environments.
• VL0241: Aluminum oxide coating on outer ring outer surface (dielectric strength up to 1000 V DC).
• VL0271: Aluminum oxide coating on inner ring outer surface (dielectric strength up to 1000 V DC).
• W203B: Bearing made of "stainless steel".

9. Mounting features & outer contour

Features on rings or housings for mounting or special installation situations.

• ADA: Wide ring grooves in the outer ring, two inner rings held in place by a retaining ring.
• ADB / DA: Modified ring grooves in the outer ring; two-piece inner ring held together by retaining ring.
• B (in housings): Bearing with spherical outer ring surface.
• B2: Tapered roller bearing to ABMA standard with flange on outer ring.
• F (in housings): Solid housing without openings (e.g. SN520F) / Four cast-in foot screw holes.
• F1 (in housings): Solid housing with openings (e.g. UCP320F1).
• F2 (in housings): Housing without mounting holes (e.g UCP322F2).
• G (in housings): Locating bearing without locating ring (e.g. SD3130G).
• G(n): Bearings with special mounting holes (n=1,2,3...).
• H: Clamping sleeves with oil injection device (e.g. AH24T48H).
• H2: Drawn cup needle roller bearing without inner ring, with narrowed enveloping circle tolerance (numbers behind = tolerance limits in µm).
• JIS: Enclosure dimensions according to JIS B 1559.
• K: Tapered bore in inner ring, taper 1:12 (mounting with adapter sleeve or on tapered shaft)).
• K7: Housing with bearing seat according to tolerance K7.
• K30: Tapered bore in inner ring, taper 1:30.
• L (in NUP-Bearings): Flange for NUP / NUP without pressure plate / NUP without flange.
• L1 (in housings): Flange bearing with grease nipple and oil drain hole (e.g. SN515L1Z).
• L5 (in housings): Flange bearing with opening for grease nipple and oil drain hole.
• MS1 / MS2: Housing base with two / four drilled screw holes.
• N: Annular groove for retaining ring in outer ring casing / Cast housing with groove for protective caps.
• N1: A retaining groove in an outer ring end face or housing washer.
• N2: Two holding grooves offset by 180° in an outer ring end face or housing disk.
• NR: Annular groove in the outer ring jacket with associated snap ring.
• NRS: Groove and retaining ring on opposite side (deviation from the standard).
• ZNR: Like NR, but also a Z-cover plate on the opposite side.
• 2ZNR: Like NR, but with Z-cover plate on both sides.
• ÖSE: Bearing without clamping element (housing).
• R (for support rollers/curve rollers): Crowned lateral surface on the outer ring (standard).
• R1: Molded outer ring flange.
• R2: Crowned track (for track rollers, support rollers and cam rollers).
• S: Round outer diameter / Spherical outer casing / No foot bolt holes (housing).
• ss: Radial insert: Bore with hexagon (not cylindrical)).
• T (in housings): Threaded hole 1/4-28 UNF for grease nipple for seal lubrication (one-sided).
• TD (in housings): Like T, but on both sides.
• U2 / U4: Narrowed width tolerance (+0.05/0 mm or +0.10/0 mm) for tapered roller bearings. / Y-bearing without eccentric ring (U2) / Y-bearing with eccentric ring without grub screw fixing (U3).
• V (in housings): Housing with grease outlet opening in the housing base.
• VE447: Shaft washer with three support threads on one end face (for puller).
• VE552 / VE553: Outer ring with three support threads on one / both end faces (for pullers)).
• VE632: Housing washer with three support threads on one end face (for puller).
• W3 / W5 / W6: Bearing with clamping screw type nozzle needle (different versions)).
• X: Cylindrical lateral surface on the outer ring (for yoke type/cam type track rollers, if crowned is standard). / Deviating main dimensions according to ISO (X1) / Cylindrical raceway surface (X2).
• Xn: Special bevel (n=1,2...).

10. bearing arrangement & pairing

Indicator for bearings intended for mounting in pairs, often with defined preload or axial clearance.

• BG: Single-row angular contact ball bearings for universal pairing without preload.
• DB: Two bearings for mounting in pairs in an O arrangement (deep groove ball bearing, angular contact ball bearing, tapered roller bearing).
• DBA / DBGA: Slight preload (L).
• DBB / DBGB: Medium preload (M).
• DBC / DBGC: Strong preload (H).
• DBCA: Axial clearance smaller than normal (CB).
• DBCB: Normal Axial clearance (CB).
• DBCC: Axial clearance greater than normal (CB).
• DBG: Special preload in daN.
• DBC (with value Wert): Special axial clearance in µm.
• DF: Two bearings for paired installation in X arrangement (details on axial clearance/preload as for DB).
• DG: Two single-row angular contact ball bearings for universal mounting in pairs (O, X or tandem arrangement) (details on axial clearance/preload as for DB).
• DR: Two bearings (deep groove ball, cylindrical roller) paired for even radial load distribution.
• DT: Two bearings for mounting in pairs in tandem arrangement. For tapered roller bearings: Number according to DT indicates intermediate rings.
• G (bei Schrägkugellagern): Bearings can be universally paired; two bearings in O or X arrangement have a fixed axial clearance.
• GA / GB / GC: Light / medium / strong preload with universally pairable bearings.
• GD2: 2 Universal bearing in a housing.
• GH / GM / GN / GL: Bearings with high / medium / normal / light preload.
• QBC: Set of four bearings: two inside in O arrangement, two outside in X or tandem arrangement (two tandem pairs in O).
• QBT: Set of four bearings: two inside in O-arrangement, two outside on one side in tandem arrangement (3x Tandem + 1x O).
• QFC: Set of four bearings: as QBC, but center pair in X arrangement (two tandem pairs in X).
• QFT: Set of four bearings: as QBT, but with X arrangement on one side (3x tandem + 1x X).
• QR: Set of four bearings (deep groove ball, roller) paired for even radial load distribution.
• QT: Set of four bearings in tandem arrangement.
• TBT: Set of three bearings: two in O arrangement, third in tandem arrangement.
• TFT: Set of three bearings: two in X arrangement, third in tandem arrangement.
• TR: Set of three bearings (deep groove ball, cylindrical roller) paired for even radial load distribution.
• TT: Set of three bearings in tandem arrangement.
• UH / UM / UL: High / medium / light preload when installed.

11. Special Applications & Variants

Identifiers for bearings that are optimized for specific operating conditions or industries.

• A1: Detachable.
• CT1: Cryogenic storage -60°C.
• DS: Slotted needle roller.
• DS1: Single-sided axial ball bearing with two shaft washers.
• DS2: Slotted radial needle roller and cage assembly.
• En: Special crowning of the rollers.
• F600 / F604: High temperature bearing for tunnel kiln cars.
• F800: Spherical roller bearings with high load carrying capacity for oscillating loads.
• FA101: High and low temperature application -40 °C to +180 °C.
• FA106: Bearings specially noise-tested.
• FA107: Bearings with lubrication holes on the mounting side.
• FA125: With Corrotect® coating.
• FA164: High temperature version up to +250 °C.
• FT150ZZ: Covered bearings for high temperatures up to +150°C.
• HG: Special rolling bearing Hug Kontr. 2-piece.
• HT2: High temperature bearing +200°C.
• HT200: Sealed bearings for high temperatures up to +200°C.
• HT200ZZ: Covered bearings for high temperatures up to +200° C.
• HVZZ: Covered bearings for high speeds up to 700 000 N.Dm.
• LTZZ: Covered bearings for low temperatures down to -60° C.
• Snn: Special control (S20: railroad / S30: wind energy).
• SORT: Tolerance positions of the needle rollers of a needle roller and cage assembly (numbers = limit values in µm).
• T04: Bearing inserts for operating temperatures down to -40° C.
• T20: Bearing inserts for operating temperatures up to +200°C.
• T41A: FAG spherical roller bearings for vibration loads (see VA405 SKF).
• TURU: Modified housing for oil lubrication with corresponding seals.
• UA: Spherical roller bearings with high load carrying capacity for vibration loads.
• VAxxx: Application-related versions (VA2xx = extreme temperatures, VA3xx = railroad applications/traction motors, VA405/406 = vibration machines, VA701 = paper machines, VA820 = wheelset bearings).
• VE240: Modified CARB bearing (greater axial displacement).
• VG052: Slotted cage made of polyethersulfone (PES).
• VH: Full complement cylindrical roller bearing with self-retaining roller set.
• Vn: Special bearing: Combines other suffixes (n = 1, 2, 3...).
• VQ015: Inner ring with crowned raceway for higher misalignment.
• VS1: Special tolerance for screen bearings.
• VU001: Pre-ground raceways.
• ZW: Double row needle roller bearing.

12. other & general license plates

• DH: Single direction thrust ball bearing with two housing washers.
• G (in tapered roller bearings): Only outer ring / Only inner ring + rollers (+cage).
• G (in Clamping sleeves): Changed thread according to ISO 2982-1.
• GS..: Housing washer of an axial cylindrical roller bearing (inside diameter slightly larger than shaft diameter).
• N (in cylindrical roller bearings): Only inner ring / Only outer ring + rollers (+cage).
• R..: Prefixed: Inner or outer ring of the bearing ... with roller set.
• TKBAnnnn / TKBNnnnn / TKZnnnn: Special traverse (nnnn: order number).
• VE: Deviations in external or internal dimensions.
• VB: Deviations in external dimensions.
• VGS: Pre-ground inner ring raceway for cylindrical roller and needle roller bearings (replaced by /VU001).
• VE900: Preliminary basic version.
• VQ: Special dimensional, shape or running accuracy.
• WS..: Shaft washer of an axial cylindrical roller bearing.