SKF Bearing Suffix Codes: What 2RS1, 2RSH, C3, JEM, GJN and P4A Mean

SKF suffixes in a catalog lookup

Suffix	SKF meaning	Changes the specification?	Source
-2RS1 / -RS1	Contact seal, NBR, on both sides / one side	Yes: closure, friction, speed limit	Designation system
-2RSH / -RSH	Contact seal, NBR, on both sides / one side; heavy-duty seal that replaces RS1 in many sizes	Yes: different seal design from RS1	Designation system, SKF Evolution on RSH
-2RSL / -RSL	Low-friction seal, NBR	Yes	Designation system
-2RZ / -RZ	Non-contact seal, NBR	Yes	Designation system
-2Z / -Z	Shield on both sides / one side	Yes	Designation system
C2, C3, C4, C5	Radial internal clearance: C2 smaller than Normal, C3 greater than Normal, C4 and C5 progressively larger	Yes: fit and running behaviour	Designation system
GJN	Grease: polyurea thickener, NLGI class 2, listed range -30 to +150 °C; the electric-motor handbook identifies it as Mobil Polyrex EM	Yes: lubrication and temperature range	Electric-motor handbook, DGBB booklet
JEM	Aftermarket package designation: J = steel cage, EM = electric motor quality; bundles C3 clearance, steel cage and low-noise quality; not marked on the bearing	Indirectly: implies C3 and a steel cage	Designation system, Electric-motor handbook
P4A	Super-precision tolerance class: dimensional accuracy to ISO class 4, running accuracy better than that class	Yes: different precision product	Super-precision catalogue
/HC	Ceramic (silicon nitride) rolling elements	Yes: hybrid bearing	Super-precision catalogue
B, E (single row angular contact)	B = 40° contact angle, E = optimized internal design (A = 30°, AC = 25°)	Yes: load direction and capacity	Single row angular contact designation system
CD / ACD (70 D super-precision)	15° / 25° contact angle	Yes	718 (SEA) series catalogue
DB, DF, DT	Matched sets: back-to-back, face-to-face, tandem	Yes: arrangement	Single row angular contact designation system

SKF’s older and current publications do not always show the same suffix list, so a feed that mixes editions may carry codes the current catalogue no longer shows. Where only a shield or a seal differs, the base number and boundary dimensions are identical.

Worked example: three records for 6205

SKF’s own product pages show how one base number splits:

SKF designation	Closure	Radial clearance	Limiting speed on the page
6205	open	CN	not retrieved
6205 JEM	no seals, no lubricant listed	C3	18,000 r/min
6205 2RSJEM	contact seals both sides, grease filled	C3	8,500 r/min

The base number, bore, outside diameter and width (25 x 52 x 15 mm) are identical. The closure, clearance and speed limit are not. In a feed these should be three distinct records, not one 6205 with a note.

What JEM means for a catalog record

JEM is easy to mishandle. SKF describes it as appearing only on the package; the bearing is marked with its real markings such as C3 and/or GJN. So a distributor listing “6205 2RSJEM” is using an SKF product designation, while a bearing physically marked 6205-2RSH/C3GJN may arrive in a JEM box. Store the product designation and derive attributes (clearance C3, cage steel, closure) from the documented fields, not from the letters JEM alone.

Critical versus secondary suffixes

• Treat as specification (block auto-merge): seal and shield, clearance, tolerance class, contact angle, arrangement, preload and ceramic elements.
• Treat as a review flag: grease suffixes such as GJN. SKF gives a thickener, NLGI class and temperature range for GJN, and its electric-motor handbook shows a calculated rating life for a 6205-2RSH/C3 rising from 25,200 h with standard grease to 57,700 h with GJN grease in that example, so grease can matter for the application.
• Store but do not decode: package-only codes and any suffix that is not in the SKF documentation.

Unknown or ambiguous codes

1. Keep the raw string. 2. Decode only the suffixes found in SKF documentation. 3. Mark the remainder “unverified” and route the record to review. 4. Never fill clearance, seal or tolerance from a similar code on another brand: the same letters differ between makers, as set out in the cross-manufacturer suffix reference.

The bearing designation decoder does the splitting for common codes and flags what it cannot resolve. For the seal question alone, see what does 2RS mean, and for pairing records across brands, is it the same bearing?.

Sources

Retrieved 12 October 2026; catalogue edition dates are not shown on these pages, and SKF notes that availability of non-Normal clearances should be checked before ordering.

• SKF, deep groove ball bearings designation system: seals, shields, clearance, JEM package note.
• SKF, bearing handbook for electric motors: GJN = Mobil Polyrex EM; JEM not marked on bearing; 6203-2RSH/C3GJN; 6205-2RSH/C3 life example.
• SKF, deep groove ball bearings booklet: GJN polyurea, NLGI 2, -30 to +150 °C.
• SKF RSL and RSH seals brochure and SKF Evolution article: RSH replaces RS1; grease retention and water exclusion.
• SKF product pages: 6205 2RSJEM, 6205 JEM, 6205.
• SKF super-precision angular contact ball bearings, high-capacity and 718 (SEA) series: CD, ACD, P4A, HC.
• SKF, single row angular contact ball bearings designation system: A, AC, B, E; DB, DF, DT.

Needs review: the exact point at which SKF moved a given size from RS1 to RSH (the handbook and later notes differ by edition), and the open-6205 limiting speed.

Related

FAQ

What does JEM mean on an SKF bearing? +

SKF describes JEM as an aftermarket designation that appears only on the package, for deep groove ball bearings used mainly in electric motors. J stands for a steel cage and EM for electric motor quality. The bearing itself is not marked JEM; it carries markings such as C3 or GJN.

Is SKF 2RS1 the same as 2RSH? +

Both are listed by SKF as a contact seal made of NBR, but they are different seal designs. SKF says the RSH seal replaces the RS1 seal in many sizes, with a different lip arrangement and better grease retention and water exclusion, so keep them as separate values.