Bearing Suffix Reference: What the Codes After the Number Mean, by Maker

How a designation is built

A complete designation is a basic designation plus optional prefixes and suffixes. SKF describes the basic designation as bearing type, dimension series and bore size code, with the bore code multiplied by 5 giving the bore in millimetres. NSK likewise describes a bearing series followed by a bore number and contact angle, with design, material and cage codes as separate supplementary designations. That structure is why the base number is portable and the suffixes are not.

SKF also states that when several special features are identified, the suffixes appear in a fixed order (with seal and shield codes in the external-design group). Read left to right, but do not assume another maker uses the same order.

Suffix families

Closure: seals and shields

Feature	SKF	FAG (Schaeffler)	NSK	NTN	Timken
Open	none	none	none	none	none
Shield, both sides	2Z	2Z (gap seal)	ZZ	ZZ	ZZ
Contact seal, both sides	2RS1, 2RSH	2RSR	DDU (also DD listed)	LLU	2RS
Non-contact seal, both sides	2RZ	not retrieved	VV	LLB	2RZ

Sources: SKF designation system; Schaeffler food-industry and Generation C publications; NSK deep-groove overview and product pages; NTN catalog 2203E; Timken catalog (see Sources). A code row does not make products identical: SKF documents RSH as replacing RS1 with a different lip arrangement, and publishes different speed limits for different closures.

Radial internal clearance

Code	Meaning	Documented by
(none) / CN	Normal clearance	NTN: blank means normal
C2	Smaller than Normal	SKF, NTN
C3	Greater than Normal	SKF, NTN, FAG
C4	Greater than C3	SKF (progressively larger), NTN
C5	Greater than C4	SKF (progressively larger), NTN

Clearance is the one family that is largely shared across makers. NTN’s own FAQ stresses that C3 is an internal clearance, not a fit.

Precision (tolerance) class

Maker	Code	Documented meaning
NSK	none, P6, P5, P4	none = ISO Class 0 (Normal); P6 = ISO Class 6; P5 = ISO Class 5; P4 = ISO Class 4
SKF	P4A	Dimensional accuracy to ISO class 4, running accuracy better than that class
FAG	P4S	Schaeffler: FAG standard better than P4 to ISO 492:2023

ISO 492 classes and ABMA ABEC grades are close but not identical systems; NTN notes that JIS B 1514 tolerances are slightly different from ABMA standards. Do not convert ABEC to ISO in a feed without the maker’s statement for that product. SKF also says the tolerance class cannot always be read from the designation suffixes.

Contact angle (angular contact bearings)

Maker	Codes documented
SKF single row	A = 30°, AC = 25°, B = 40°, E = optimized internal design
SKF super-precision 70 D series	CD = 15°, ACD = 25°
NSK	C = 15°, A5 = 25°, A = 30°, B = 40°
FAG spindle	C = 15°, E = 25°

The same letter means different angles in different families (SKF B is 40° on a 72 B(E) bearing; SKF CB is a 15° high-speed design in the super-precision range). Always read the code against the product family.

Cage, arrangement, preload and grease

Feature	Documented examples
Cage	SKF: standard stamped steel ball-centred cage is not marked; other cages have their own suffixes. FAG: T = laminated fabric (spindle); JN = sheet steel (6207-2RSR page)
Arrangement	SKF DB back-to-back, DF face-to-face, DT tandem; FAG U = single bearing; NSK SU = single universal
Preload	FAG L = light; NSK L = light, with EL, M, H also used; SKF G, GA, GB, GC for universally matchable bearings (letters differ by family)
Grease	SKF GJN = polyurea grease, NLGI 2 (Mobil Polyrex EM per the electric-motor handbook)
Ceramic balls	SKF /HC; FAG HC / HCB (ceramic balls)

Worked designations

Each row decodes only what a maker source states. Anything else is left blank on purpose.

Designation	Maker	Decoded	Not decoded here
6203-2RSH/C3GJN	SKF	6 = deep groove ball, 03 bore code, 2RSH NBR contact seals both sides, C3 clearance, GJN grease	none
6205 2RSJEM	SKF	25 x 52 x 15 mm family, seals both sides (contact), grease filled, C3; JEM is an aftermarket package designation	see JEM note in the SKF guide
6205ZZC3/2AS	NTN	ZZ shield, C3 clearance, a grease suffix /2AS (NTN catalog example)	what /2AS specifies
6805DDC4P6	NSK	DD rubber contact seals both sides, C4 clearance, P6 = ISO Class 6	none
6302VVC3	NSK	VV rubber non-contact seals both sides, C3 clearance	none
6208-2RSR-L038-C3	FAG	2RSR seals both sides, C3 (larger than CN)	L038
62 05 H 2RS C3	Timken	material letter H (stainless, corrosion-resistant catalog), 2RS contact seals, C3	none
7205 BEP	SKF	7 = single row angular contact, 2 series, 05 = 25 mm bore, B = 40° contact angle, E = optimized internal design	P
7014 CD/P4A	SKF	70 mm bore (14 x 5), CD = 15° high-capacity design, P4A tolerance class	none
B7014-E-T-P4S-UL	FAG	70 mm bore, E = 25°, T = laminated fabric cage, P4S tolerance, U = single bearing, L = light preload	the B prefix
7006CTYNSULP4	NSK	30 mm bore, C = 15°, SU = single universal, L = light preload, P4 = ISO Class 4	TYN (cage code unconfirmed)

Catalog consequences

1. Store three things per suffix: the raw string, the decoded attribute (closure, clearance, precision class, cage, grease) and the source it was decoded from.
2. Decode per maker. A lookup keyed on the letters alone will mislabel the same code across brands.
3. Unknown means unknown. Leave the field empty and queue the record; do not infer from a similar-looking code.
4. Suffixes that change specification block auto-merge: closure, clearance, precision, contact angle, preload and cage. A grease code or package-only code can still matter for the application, so treat it as a review flag, not as noise.
5. Normalize separators separately from meaning. FAG listings appear as 6208-2RSR-C3 in current Schaeffler pages and as 6208.2RSR.C3 in older catalogues; that is formatting, not a different product.

Cross-brand pairing rules are in is it the same bearing?. The bearing designation decoder splits a designation into fields, and the ball bearing attribute template lists the attributes these codes should populate. For SKF codes in depth, see the SKF suffix guide. For the shortest version of the seal question, see what does 2RS mean.

Sources

Retrieved 12 October 2026; edition dates are not shown on most of these pages.

• SKF, deep groove ball bearings designation system: suffix order; -2RS1, -2RSH, -2Z, -2RZ, -2RSL; C2 to C5; standard cage not marked.
• SKF, basic bearing designation system: basic designation = type, dimension series, bore code; size code x 5 = bore.
• SKF, single row angular contact ball bearings designation system: A, AC, B, E; DB, DF, DT.
• SKF 7205 BEP product page: 25 mm bore, 52 mm OD, 15 mm width, 40° contact angle.
• SKF super-precision angular contact ball bearings, high-capacity catalogue: CD 15° and P4A; 7014 CD/P4A 70 x 110 x 20 mm.
• SKF bearing handbook for electric motors: GJN = Mobil Polyrex EM grease; example 6203-2RSH/C3GJN; JEM is package only.
• SKF 6205 2RSJEM: contact seals both sides, grease, C3.
• SKF, RSH heavy-duty seals: RSH replaces RS1 with a different lip arrangement.
• Schaeffler B7014-E-T-P4S-UL: E = 25°, T = laminated fabric cage, U = single bearing, L = light preload, P4S.
• Schaeffler HCB7007-C-T-P4S-UL: C = 15°, ceramic balls, P4S better than P4 to ISO 492:2023.
• Schaeffler 6207-2RSR: 2RSR contact seals both sides, sheet steel cage (JN). Schaeffler 6208-2RSR-L038-C3: C3 larger than CN.
• NSK, bearing designations: bearing series, bore number, contact angle; supplementary codes. NSK, angular contact ball bearings: C 15°, A5 25°, A 30°, B 40°.
• NSK 7006CTYNSULP4: 30 x 55 x 13 mm, 15°, ISO Class 4 (P4), preload classes EL, L, M, H.
• NSK deep groove ball bearings: D, DU, V sealed; Z shielded. NSK product pages 6805DDC4P6 and 6302VVC3.
• NTN catalog 2203E, deep groove ball bearings: ZZ, LLB, LLU; C1 to C5; example 6205ZZC3/2AS. NTN FAQ: C3 is not a fit. NTN catalog, bearing tolerances: JIS B 1514, ISO 492, ABMA.
• Timken deep groove ball bearing catalog: Z, ZZ, RS, 2RS, RZ, 2RZ. Timken corrosion-resistant catalog: material letter H, example 62 05 H 2RS C3.

Needs review

• NSK clearance symbol “CM” (seen in product names such as 6001DDUCM): the only description found was a distributor listing, so it is not defined here.
• NSK TYN cage code, NTN /2AS grease suffix, FAG L038 and the SKF P in 7205 BEP: no maker definition was retrieved.
• FAG non-contact seal code for deep groove bearings and the FAG B prefix: not retrieved.
• Timken 2RZ as a non-contact seal was read from a catalog listing of RZ and 2RZ; confirm against the current Timken catalog.

Related

FAQ

Are bearing suffixes standardized across manufacturers? +

Only partly. The base number (type, dimension series, bore) follows ISO conventions, and clearance classes such as C3 are widely shared. Seal, shield, cage, grease and precision suffixes are set by each maker, so the same letters can mean different things and the same feature can have different letters.

What should a catalog do with a suffix it cannot decode? +

Keep the raw suffix string, leave the decoded attribute empty rather than guessing, and flag the record for review against the maker’s catalogue. An unknown suffix is evidence that the product may differ, so it should block an automatic merge.