Bearing Nomenclature
PKB Ball Bearing Nomenclature
PACAMOR KUBAR BEARINGS offers an array of retainer designs and materials, including but not limited to, Crown, Ribbon, heat and moisture resistant Phenolic, and Torlon (polyamide-imide). In addition to selecting the right retainer for your miniature bearing application, dissimilar materials can prevent component micro-welding and extend the life of the bearing.
To this end, we offer standard stainless steel or optional ceramic balls or titanium carbide-coated 440C stainless steel balls(Tic), in our miniature bearing designs.
PACAMOR KUBAR BEARINGS precision miniature bearings are available with up-to ABEC 9 tolerances (as defined by the American Bearing Manufacturers’ Association), with optional flanged-outer rings.
Description of PACAMOR KUBAR BEARINGS part numbering system and methodology, for identifying a PKB part number.
Special Feature | Material | Type | Style | Retainer | Basic Size | Closure |
---|---|---|---|---|---|---|
X | S | F | R | B | 2-5 | ZZ |
S | (ZZ) | R | PH | 144 | Z |
Special Feature
X followed by two numbers = Special feature or change in standard dimension, to basic bearing number.
A = Tapered Outside Diameter (OD)
Material
S = AISI44OC stainless steel
Type
F = Flanged bearing
No Symbol = straight OD
(ZZ) = Open bearing, but with shielded width
Style
R = Radial Inch
Blank or MM = Metric
AINS = Angular Contact Inner-Relieved, Non-Separable
AIS = Angular Contact Inner-Relieved, Separable
AONS = Angular Contact Outer-Relieved, Non-Separable
AOS = Angular Contact Outer-Relieved, Separable
Retainer Type
Standard retainer could be either one piece crown or two piece ribbon type.
Blank = Pacamor’s standard option
B = Two Piece Ribbon
PH = Phenolic Crown Retainer
F = Full-Complement (No Retainer)
FU = Full-Complement (Metric Size)
SL = Slug Separators
TO = Teflon Toroids
PG = PGM
PE = PEEK
T = Torlon
*Other machined retainer options available
Basic Size (Bearing Chassis)
See basic bearing numbers listed in our catalog
Closures
Z = Single shield | LL = Double glass-reinforced Teflon seal |
ZZ = Double shield | RS = Single rubber seal |
Z1 = Shield on flanged side | 2RS = Double rubber seal |
Z2 = Shield opposite flanged side | V = Single non-contact seal |
T = Single Teflon seal | VV = Double non-contact seal |
TT = Double Teflon seal | UZ = Single shielded, narrow width bearings |
L = Single glass-reinforced Teflon seal |
No designation = open bearing
Ring Feature | Alt. Ball Material | Radial Play | ABEC Tolerance | Functional Test | Lubrication | Coding / Duplex | Package |
---|---|---|---|---|---|---|---|
EE | CB | K25 | A5 | ST10 | L245X | ZD | P |
TiC | K24 | A7 | EMQ | ROY27 | DB | B |
Ring Feature
EE = Extended inner rings
NR = Snap ring on bearing OD
Blank = 440c Stainless Steel Balls
Alternate Ball Material
CB = Ceramic (Silicon Nitride) balls
TiC = TiC-coated 440c stainless steel balls
Radial Play
Symbol K followed by number indicates radial play in tenths of thousands of an inch.
Examples:
K25 = 0.0002″ to 0.0005″
K58 = 0.0005″ to 0.0008″
ABEC Tolerances
A1 = ABEC 1
A3 = ABEC 3
A5 = ABEC 5P
A7 = ABEC 7P
A9 = ABEC 9P*
*ABEC9 tolerances are available upon request
Functional Test
Blank = Pacamor’s standard option
ST followed by number = indicates starting torque in hundreds of MG-MM
E.M.Q. = Electric Motor Quality
Lubrication
Blank = Pacamor’s standard option
See our common lube codes here
LD = Dry bearings (no lubrication) | |
GP = Indicates grease plate | |
BC = Indicates barrier coating | |
OP = Oil plate | |
DIC = Dicronite coating |
Alternate lubes/coatings available upon request.
Coding
Tolerance | 0.0001 Increment Coding (Standard), In | 0.000050 Increment Coding, In |
---|---|---|
Nominal to -0.000050, In | 1 | A |
-0.000050 to -0.000100, In | B | |
-0.000100 to -0.000150, In | 2 | C |
-0.000150 to -0.000200, In | D | |
-0.000200 to -0.000250, In | 3 | E |
-0.000250 to -0.000300, In | F | |
Grade Symbols | ||
Graded Bore and OD | ZD | XZD |
Graded Bore Only | ZB | XZB |
Graded OD Only | ZO | XZO |
Duplex Coding (also known as Duplex Sets or Duplex Pairs)
DB = Back to Back Pairing | — DT = Tandem Pairing |
DF = Face to Face Pairing | — DU = Universal Pairing |
Packaging
The following symbols indicate various types available:
Blank = Vial packaging
P = Individual pill packaging
B symbol = Individual box
M symbol = Individual pack per Mil-197
Contact PKB for more offerings.