NSK is one of the leading bearing manufacturers with a long tradition of patent applications for machine parts. NSK not only concentrates on the development of new technologies but also on continuous quality improvement based on the integrated technology platform of tribology, materials technology, analysis, and mechatronics.
With more than 20,000 employees worldwide and over 64 production plants. NSK manufactures approximately three million new bearings per day (from miniature bearings with a one-millimetre bore to bearings with a diameter of five meters).
With so many many types of bearings and part numbers, bearing order codes are made up of a combination of letters and numbers. This alphanumeric combination denotes the type, size, and structure of the bearing.
Within each order code, a distinction is made between the basic designation and any suffixes and/or prefixes. The basic designation indicates the bearing type and the hole size. These basic designations are defined in the German Standard DIN 623 and the corresponding ISO standard.
For most types of bearings, the basic designation is made up of numbers, but some are alphanumeric. Prefixes and suffixes denote special modifications, for example, if internal clearance or precision deviates from the norm.
The use of prefixes and suffixes are only partially standardized. Suffixes differ the most, with the various bearing manufacturers using different codes for certain modifications. This guide explains the various bearing codes used by NSK and RHP and helps you compare them with designations from other manufacturers.
NSK Suffixes and Bearing Part Number System
NSK bearings use a large number of suffixes to indicate structural modifications in different types of bearings.
Specifically, suffixes provide information about:
- Meter type
- Internal layout
- Stamp
- Used lubricant
- Tolerances
- Interior space
- External design
NSK bearing suffixes.
The table below shows the complete list of suffixes
| Suffix | Definition |
| +AH | WITHDRAWAL OR REMOVAL SLEEVE. |
| +H | ADAPTER SLEEVE. |
| +HJ | STABILIZING RING/ CYLINDRICAL ROLLER BEARINGS. |
| +K | OUTER RING SPACER, TAPERED ROLLER BEARINGS. |
| +KL | INNER AND OUTER RING SPACER, TAPERED ROLLER BEARINGS. |
| +L | INNER RING SPACER, TAPERED ROLLER BEARINGS. |
| -8 | BORE SIZE, 1/2 INCH DIAMETER. |
| -10 | BORE SIZE, 5/8 INCH DIAMETER. |
| -100 | BORE SIZE, 1 INCH DIAMETER. |
| -107 | BORE SIZE, 1-7/16 INCH DIAMETER. |
| -12 | BORE SIZE, 3/4 INCH DIAMETER. |
| -13M | BORE SIZE, 13 MM DIAMETER. |
| -14 | BORE SIZE, 7/8 INCH DIAMETER. |
| -625 | BORE SIZE, 0.6250 INCH DIAMETER. |
| -8 | BORE SIZE, 1/2 INCH DIAMETER. |
| 1 | 1/8 FULL. |
| 2 | 1/4 FULL. |
| 3 | 3/8 FULL. |
| 4 | 1/2 FULL. |
| 5 | 5/8 FULL. |
| 6 | 3/4 FULL. |
| 7 | 7/8 FULL. |
| 8 | 100 PERCENT FULL |
| 9 | DIP. |
| A | INTERNAL REDESIGN. |
| A | 30 DEGREE CONTACT ANGLE, ANGULAR CONTACT BALL BEARINGS. |
| AB | ANDOK B. |
| AC | ANDOK C. |
| AE | AEROSHELL 15. |
| AE3 | ABEC-3 TOLERANCE. |
| AE5 | ABEC-5 TOLERANCE. |
| AF | AEROSHELL 17. |
| AK | ANDOK 260. |
| AN | ANDEROL L-423 OIL. |
| AR | AEROSHELL 5. |
| AS | AEROSHELL 7. |
| AT | AEROSHELL 16. |
| AW | AEROSHELL 22. |
| AX | AEROSHELL 6. |
| B | INTERNAL REDESIGN. |
| B | 40 DEGREE CONTACT ANGLE, ANGULAR CONTACT BALL BEARINGS. |
| BS | X8388A (BATCO) . |
| BT | BEACON 325. |
| C | INTERNAL REDESIGN. |
| C | 15 DEGREE CONTACT ANGLE, ANGULAR CONTACT BALL BEARINGS. |
| C2 | TIGHT FIT, AFBMA CLASS 2. |
| C3 | LOOSE FIT, AFEMA CLASS 3. |
| C4 | EXTRA LOOSE FIT, AFBMA CLASS 4. |
| CA | SPHERICAL ROLLER BEARING. |
| CC | STANDARD, NON-INTERCHANGEABLE FIT, CYLINDRICAL ROLLER BEARINGS. |
| CC2 | LESS THAN STANDARD NON-INTERCHANGEABLE FIT, CYLINDRICAL BEARINGS. |
| CC4 | GREATER THAN CC3 FIT, CYLINDRICAL ROLLER BEARINGS. |
| CCS | GREATER THAN CC FIT, CYLINDRICAL ROLLER BEARINGS. |
| CD | SPHERICAL ROLLER BEARING. |
| CE | ELECTRIC MOTOR QUALITY BEARING AND FIT. |
| CH | CHEVRON OHT. |
| CHS | WATER PUMP BEARING WITH SLINGER RING. |
| CM | ELECTRIC MOTOR QUALITY BEARING AND FIT. |
| CT | ELECTRIC MOTOR QUALITY BEARING AND FIT. |
| D | STEEP CONTACT ANGLE, TAPERED ROLLER BEARING. |
| DA | DOW CORNING DC99 – NO. 2. |
| DB | SUPERNAL GREASE NO. 72832. |
| DB | DOW CORNING FS3451 – NO. 2. |
| DB | DUPLEX PAIR, BACK-TO-BACK MOUNTING. |
| DDU | TWO RUBBER CONTACT SEALS. |
| DE | DC41. |
| DF | DC44. |
| DH | DOW CORNING 510. |
| DH | WATER PUMP BEARING, DULITED AND HANED PARTS. |
| DP | DUPLEX PAIR, FACE-TO-FACE MOUNTING. |
| DS | DC FS 1291. |
| DT | DC33. |
| DT | DUPLEX PAIR, TANDEM MOUNTING. |
| DU | SINGLE RUBBER CONTACT SEAL. |
| DV | DC FS 1292. |
| E | BEARING WITH SLOT OR KEYWAY. |
| E100 | SPECIAL BEARINGS (MIL-B-17931C) . |
| E101 | GREASE QUANTITY AND TEFLON SEAL ELEMENT, SPECIAL. |
| E4 | OUTER RING RELUBRICATION FEATURE, SPHERICAL BEARINGS. |
| ES11 | SPECIAL GREASE VOLUME. |
| ES12 | SPECIAL CARTON MARKING. |
| ES13 | SPECIAL CORNER RADIUS. |
| ES15 | SPECIAL END PLAY. |
| ES16 | SPECIAL PROCESSING. |
| ES17 | SPECIAL CLEANING. |
| ES18 | RADIAL PLAY LIMITS SPECIAL. |
| ES19 | SPECIAL CLEANING, LUBRICATION. |
| ES20 | RADIAL PLAY, GAGING LOADS, SPECIAL. |
| ES21 | HEAT STAB, FOR 325°F OPERATION. |
| ES22 | XT RADIAL PLAY, SPECIAL. |
| ES24 | (MIL-B-17931A) , AMENDMENT 2, LOW NOISE LEVEL. |
| ES25 | HIGH-SPEED TEST. |
| ES26 | DULITE PROCESSED. |
| ES27 | END PLAY AND TILT LIMITS, SPECIAL. |
| ES28 | DULITE PROCESSED. |
| ES29 | SPECIAL SHIELD MARKING. |
| ES3 | 100 PERCENT SPEED TEST, LOW NOISE LEVEL. |
| ES30 | QUALITY AUDIT, SPECIAL. |
| ES31 | TORQUE LIMITS, SPECIAL. |
| ES32 | SPECIAL INSPECTION. |
| ES33 | LOW NOISE LEVEL. |
| ES34 | ULTRASONIC CLEANING. |
| ES35 | FLUSHNESS TOLERANCE SPECIAL. |
| ES36 | SPECIAL IDENTIFICATION. |
| ES37 | DULITE SHIELD. |
| ES38 | SPECIAL END PLAY. |
| ES39 | ELECTRONIC NOISE TESTING. |
| ES40 | HEAT STABILIZED, SPECIAL. |
| ES41 | STABILIZATION FOR 375 DEG F OPERATION. |
| ES42 | «HS 2» MARKING ON OUTER. |
| ES43 | GREASE CONTROL, SPECIAL. |
| ES44 | REDUCED INSPECTION LIMITS. |
| ES45 | LAPPED INNER FACE. |
| ES46 | OVERSIZE O.D. ‘ S. |
| ES47 | SPECIAL FOR RAILROAD APPLICATION. |
| ES48 | SPECIAL O.D. TOLERANCE. |
| ES49 | SHIELD IDENTIFICATION, SPECIAL. |
| ES50 | REWORK IDENTIFICATION. |
| ES51 | SPECIAL TOLERANCES. |
| ES52 | SOLVENT CLEAN PARTS , SPECIAL . |
| ES53 | SPECIAL PROCESSING. |
| ES54 | SPECIAL FOR RAILROAD APPLICATIONS. |
| ES55 | SPECIAL 77R6. / |
| ES56 | RADIAL LOOSENESS CHECK ,_ SPECIAL . |
| ES57 | SPECIAL O.D. CORNER. |
| ES58 | HIGH POINT MARKING ON INNER RING. |
| ES59 | O.D. CODING. |
| ES6 | CERTIFIED QUALITY CONTROL. |
| ES60 | SPECIAL GREASING. |
| ES61 | ES-41 AND SPECIAL GREASING. |
| ES62 | SHIELD OR SEAL ASSEMBLY, SPECIAL. |
| ES63 | SPECIAL 7038. |
| ES65 | SPECIAL MARKING INSTRUCTIONS. |
| ES66 | SPECIAL IDENTIFICATION. |
| ES67 | SPECIAL GREASE AND QUANTITY. |
| ES68 | SPECIAL GREASE QUANTITY. |
| ES7 | SPECIAL PROCESS, SPECIAL CARTON MARKING. |
| ES70 | SPECIAL MARKING. |
| ES71 | SPECIAL WIDTH TOLERANCE. |
| ES72 | SPECIAL LUBRICATION. |
| ES73 | SPECIAL PROCESSING. |
| ES74 | SPECIAL RING MARKING. |
| ES75 | BEARINGS SERIAL NUMBERED. |
| ES82 | RELUBE TYPE SHIELDS. |
| ES83 | ELECTRO-GALVANIZING . |
| ES84 | SPEC, INTERNAL CLEARANCE AND SPECIAL GREASE QUANTITY. |
| ES85 | SPECIAL GREASE QUANTITY. |
| ES9 | (MIL-B-17931A) , AMENDMENT 1, LOW NOISE LEVEL. |
| ESI | HAND SPIN TEST, LOW TORQUE. |
| ESS | SHIELD CLEARANCE 0.003 INCH, SPEC, TOLERANCE. |
| ESS | LOW NOISE LEVEL. |
| F | SINGLE SHIELD, DOUBLE-ROW BALL BEARINGS. |
| FF | TWO SHIELDS, DOUBLE-ROW BALL BEARINGS. |
| FM | FISKE LUBRIPLATE – MULTI-LUBE A. |
| FT | FISKE LUBRIPLATE 210. |
| G | SNAP RING ON BEARING. |
| GNR | SNAP RING GROOVE ON BEARING, NO SNAP RING. |
| GS | SNAP RING ON SAME SIDE OF BEARING AS SHIELD. |
| HP | HUMBLE OIL UNIVIS P38. |
| HX | HUMBLE OIL UNIREX NO. 2. |
| J | PRESSED STEEL RETAINER, TWO PIECE RIBBON TYPE. |
| K | TAPERED BORE BEARING 1:12. |
| K30 | TAPERED BORE BEARING 1:30. |
| KH | KEYSTONE 89H. |
| KY | DUPONT, KRYTOX 240AC. |
| LU | LUBRIKO M24. |
| M | MACHINED BRONZE RETAINER. |
| M | MEDIUM FIT, AFBMA CLASS 0. |
| MT | MOBIL-TEMP £1 SOCONY VACUUM. |
| N | SNAP RING GROOVE IN OUTER RING. |
| NF | NON-FLUID OIL CP. F924. |
| NG | NON-FLUID OIL CO. G-60. |
| NR | NOX – RUST 509. |
| NR | SNAP RING IN OUTER RING. |
| NS | NON-FLUID OIL CO. S-59. |
| NW | NON-FLUID OIL CO. W-56. |
| OS2 | WATER PUMP BEARING, SHAFT 0.002 INCH OVERSIZE. |
| OS3 | WATER PUMP BEARING, SHAFT 0.003 INCH OVERSIZE. |
| PE | PETROLATUM |
| RR | O.D. RIDING TRASH GUARD RUBBER CONTACT SEALS. |
| RS | FACE RIDING RUBBER CONTACT SALES. |
| RY | RYKON 12. |
| SA | SHELL ALVANIA $2 |
| SB | SHELL XSG6409. |
| SC | SHELL CYPRINA £3. |
| SD | SHELL DARINA J2. |
| SE | SHELL DARINA EP. |
| SF | SHELL DARINA FL. |
| SG | STANDARD GREASE CODE. |
| SL | SHELL ALVANIA 13. |
| SO | STANOIL 15. |
| SP | SHELL ALVANIA $2 EP. |
| SW | SOUTHWEST GREASE AND OIL CO., CODE 5682. |
| SX | SHELL DARINA AX. |
| T | FACE RIDING TRASH GUARD RUBBER CONTACT SEAL. |
| T | TIGHT FIT, AFBMA CLASS 2. |
| TB | TEXACO PREMIUM BRB. |
| TC | TEXAS CAPELLA B. |
| TE | TEXAS EP 2324 HI-TEMP. |
| TH | TEXAS 1999 HI-TEMP. |
| TL | ASHLAND OIL TECTYL 900. |
| TM | TEMPLUBE 124. |
| TR | TEXAS REGAL STARFAK AFB-2 . |
| TT | TWO FACE RIDING TRASH GUARD RUBBER CONTACT SEALS. |
| TU | TEXAS 1996 UNI-TEMP 500. |
| TX | TEXAS 1692. |
| UC | SUPERMIL GREASE NO. 31052. |
| UF | ASU 40. |
| UN | UNOBA JL UNION OIL. |
| US | ASU 06752 (AMERICAN OIL) . |
| UT | ASU 100. |
| V | LABYRINTH RUBBER SEAL . |
| VA | CHEVRON BRB2 |
| VS | CHEVRON SRI |
| W | TWO LABYRINTH RUBBER SEALS. |
| W | PRESSED STEEL RETAINER, ONE PIECE TYPE. |
| WN | WINDSOR L245X |
| X | REDESIGNED BOUNDARY DIMENSION OF LESS THAN + 1 MM. |
| XL | EXTRA LOOSE FIT, AFBMA CLASS 3. |
| XT | EXTRA TIGHT FIT, LESS THAN AFBMA CLASS 2. |
| Y | PRESSED BRASS RETAINER, TWO PIECE, RIBBON TYPE. |
| Z | SINGLE SHIELD. |
| ZZ | GREASE SPE CIS PART OF ES NUMBER. |
| ZZ | TWO SHIELDS. |
NSK prefixes and bearing part number system
Prefixes are used relatively rarely. They serve almost exclusively to indicate individual components of complete bearings or to designate miniature bearings.
NSK bearings prefixes.
The following table shows the complete list of prefixes used by NSK bearings.
| Prefix | Definition |
| 7 | SINGLE SHIELD. |
| 77 | TWO SHIELDS. |
| 8 | FELT SEAL. |
| 87 | ONE FELT SEAL, ONE SHIELD. |
| 88 | TWO FELT SEALS. |
| 89 | ONE FELT SEAL, ONE TEFLON SEAL. |
| 9 | TEFLON SEALS. |
| 99 | TWO TEFLON SEALS. |
| H | HEAVY SERIES CUP OR CONE, TAPERED ROLLER BEARINGS. |
| HH | EXTRA HEAVY SERIES CUP OR CONE, TAPERED ROLLER BEARINGS. |
| HM | MEDIUM-HEAVY SERIES CUP OR, CONE , TAPERED ROLLER BEARINGS. |
| L | LIGHT SERIES CUP OR CONE, TAPERED ROLLER BEARINGS. |
| LL | EXTRA LIGHT SERIES CUP OR CONE, TAPERED ROLLER BEARINGS. |
| LM | MEDIUM-LIGHT SERIES CUP OR CONE, TAPERED ROLLER BEARINGS. |
| M | MAX-TYPE, FILLING SLOT BALL BEARINGS. |
| M | MEDIUM SERIES CUP OR CONE, TAPERED ROLLER BEARINGS. |
| MS | SHIELD AND LOADING SLOT ON SAME SIDE, BALL BEARINGS. |
| N | CYLINDRICAL BEARING, DOUBLE FLANGED INNER, OPEN OUTER. |
| NF | CYLINDRICAL BEARING, DOUBLE FLANGED INNER, SINGLE FLANGED OUTER. |
| NH | CYLINDRICAL BEARING, TWO-PIECE INNER, DOUBLE FLANGED OUTER. |
| NJ | CYLINDRICAL BEARING, SINGLE, FLANGED INNER, DOUBLE FLANGED OUTER. |
| NN | CYLINDRICAL BEARING, DOUBLE-ROW, FLANGED INNER, OPEN OUTER. |
| NU | CYLINDRICAL BEARING, OPEN INNER, DOUBLE FLANGED OUTER. |
| R | INCH DIMENSION SERIES BALL BEARINGS. |
| RA | POWER TRANSMISSION BALL BEARINGS, PRELUBRICATED. |
| RAG | POWER TRANSMISSION BALL BEARINGS, RELUBRICATEABLE. |
| S | CARTRIDGE BEARING SERIES. |
| SB | POWER TRANSMISSION BEARING, WIDE INNER, PRELUBRICATED. |
| SBG | POWER TRANSMISSION BEARING, WIDE INNER, RELUBRICATEABLE. |
| SE | ECCENTRIC LOCKING COLLAR FOR POWER TRANSMISSION. |
| SF | FOUR-BOLT FLANGE UNIT, STANDARD, RELUBRICATEABLE. |
| SFC | FOUR-BOLT FLANGE UNIT, RA UNIT, PRELUBRICATED. |
| SFT | TWO-BOLT FLANGE UNIT, STANDARD, RELUBRICATEABLE. |
| SFTC | TWO-BOLT FLANGE UNIT, RA UNIT, PRELUBRICATED. |
| SP | STANDARD HEIGHT PILLOW BLOCK, RELUBRICATEABLE. |
| SPC | STANDARD HEIGHT PILLOW BLOCK, RA UNIT, PRELUBRICATED. |
| SPEC | REVISED HEIGHT PILLOW BLOCK, RA UNIT, PRELUBRICATED. |
| SPH | REVISED HEIGHT PILLOW BLOCK, RELUBRICATEABLE. |
| STU | TAKE-UP UNIT BLOCK, RELUBRICATEABLE. |
| STUC | TAKE-UP UNIT BLOCK, RA UNIT, PRELUBRICATED. |
| WC | FELT SEAL SERIES BEARINGS, WIDE OUTER RING. |
| X | SPECIAL BEARING SERIES. |