Annular Bearing Engineering Committee. Used as prefix for tolerance grades
of bearings as set up by this committee.
Bearing Engineers Committee classes or grades of ball bearing precision.
The Anti-Friction Bearing Manufacturers Association. They have set up standards
for the bearing industry.
Assembly consisting of adapter sleeve, locknut and lockwasher.
Axially slotted sleeve with cylindrical bore, tapered outside surface and
male screw thread at small end used with locknut and lockwasher for mounting
of bearings with tapered bore on cylindrical outside surface of shaft.
Also called pull-type sleeve.
A term applied generally to bearings used by the aircraft industry or the
A bearing designed for use in the control systems and surfaces of aircraft.
Angular Contact Bearing
A type of ball bearing whose internal clearances and ball race locations
are such as to result in a definite contact angle between the races and
the balls when the bearing is in use.
Annular Ball Bearing
A rolling element bearing designed primarily to support a load perpendicular
to the shaft axis. Also: Radial Type Bearing.
Commonly used term for rolling element bearing.
In the same direction as the axis of the shaft.
Axial Internal Clearance
In ball or roller bearing assembly, total maximum possible movement parallel
to bearing axis of inner ring in relation to outer ring. Also called bearing
Load exerted parallel to the axis of the shaft on which the bearing is
mounted, also called thrust load.
An imaginary line running through the center of a shaft on which a bearing
A spherical rolling element.
A bearing using balls as the rolling elements.
A device which partly surrounds the balls and travels with them, the main
purpose of which is to space the balls.
Also Separator: Retainer: Ball
Number of balls used in a ball bearing.
Area of contact between raceway and ball.
The dimension measured across the ball center.
A drilled, stamped, or molded receptacle that holds the ball in a cage.
Basic Dynamic Load Rating
Basic dynamic load rating, Cr, is the calculated constant radial load (thrust
load for thrust bearings) which a group of identical bearings with stationary
outer rings can theoretically endure for rating life of 1 million revolutions
of inner ring.
The smallest internal dimension of inner or outer ring or separator. Also,
the surface of the inner ring that fits against the shaft.
Dimensions for bore, width, outside diameter and corner radius.
See Ball Cage.
See Track roller
An extra wide double shielded or sealed bearing designed to increase grease
capacity of bearing.
Having the same center.
Inner ring of tapered roller bearing.
Standard single row deep-groove bearing named for the inventor of its assembly
method, Joseph Conrad.
Formed by a line drawn between the areas of ball and ring contact and a
line perpendicular to the bearing axis.
Counterbored Ball Bearing
Portion of one race shoulder turned and ground away to facilitate assembly
with a greater number of balls. A non-separable ball bearing with one side
of the raceway removed from either or both rings to facilitate manufacturing
assembly. Normally the outer ring is counterbored.
Double Row Bearing
A bearing with two rows of rolling elements.
Double Row Maximum Capacity
A bearing that has a solid inner and outer with two raceways and filling
notches to permit the maximum number of balls to be inserted.
Drawn Cup Needle Roller
Needle roller radial bearing with thin pressed steel outer ring (drawn
cup), which may have one closed end or both ends open. Usually employed
without inner ring.
A duplex bearing is a bearing with controlled axial location of faces of
inner and outer rings which makes this bearing suitable for mounting in
various combinations with one or more bearings controlled in the same manner.
A load exerted on a bearing in motion.
Not having the same center.
The axial play of the outer ring in a bearing. The measured maximum possible
movement parallel to bearing axis of the inner ring in relation to outer
The ball path on an inner ring. Also - Inner Raceway, Inner Ring Raceway.
The side surface of a bearing. See also Thrust Face.
The corner dimension in a bearing housing that the bearing external corner
radius or chamfer must clear.
A slot or notch cut in the shoulder of a ring to allow the loading of the
maximum number of balls. Also Filling Notch; Loading Groove.
A term usually applied to the last machining operation on any surface of
a bearing, such as "Finish O.D., " "Finish bore, " etc.
The amount of internal clearance in a bearing. Fit can also be used to
describe shaft and housing size and how they relate to the bore or outside
Bearing which positions shaft against axial movement in both directions.
Bearing designed or mounted so as to permit axial displacement between
shaft and housing.
Full Complement Bearing
Rolling bearing without cage in which sum of clearances between rolling
elements in each row is less than the diameter of rolling elements and
small enough to give satisfactory function of bearing.
Process of heating parts to a high temperature and then quenching in oil,
water, air, or solution.
Process of hitting rivets in a press to form the heads.
The opening in which a bearing is contained in a machine. The part of a
machine that contains this opening.
Amount of interference or clearance between bearing outside surface and
housing bearing seat.
Collar temporarily fixed to shaft which incorporates hydraulic annular
piston to transmit axial mounting or dismounting force to bearing inner
International Standards Organization.
Inch Dimension Bearing
A bearing having boundary dimensions made to integral or/and fractional
inch figures rather than metric figures.
See Inner Ring
The inner part of a bearing that fits on a shaft and contains the external
raceway for the rolling elements. Sometimes the shaft is stationary and
the housing rotates.
Inner Ring Raceway
See External Race.
See Radial Clearance.
The ball or roller path on the bore of the outer ring. Outer Ring Raceway.
Commonly called the O.D. of the inner and the I.D. of the outer.
An abrading process for refining the surface finish and the geometrical
accuracy of a surface.
"Life" of individual rolling bearing is the number of revolutions (or hours
at some given constant speed) which bearing runs before first evidence
of fatigue develops in the material of either ring or washer or any of
Maximum and minimum allowable dimensions, resulting from the application
of predetermined tolerances to a specified dimension.
A nut used in combination with a lock washer to hold a bearing in place
on a shaft.
A washer with tongue and prongs to hold a lock nut in place.
Locking Collar, Concentric
Ring fitting over extended inner ring of insert bearing and having setscrews
which pass through holes in inner ring to make contact with shaft.
Locking Collar, Self
Ring having recess on one side which is eccentric in relation to bore and
fits over equally eccentric extension of inner ring insert bearing. Collar
is turned in relation to inner ring until it locks and then secured to
shaft by tightening of setscrews.
A fit or fit up of inner ring, balls, and outer ring which results in the
existence of appreciable radial clearance.
Maximum Capacity Bearing
A bearing with filling notches to allow the loading of the maximum number
Lack of parallelism between axis of rotating member and stationary member.
Cylindrical roller of small diameter with large ration of length to diameter.
Generally accepted that length is between three and ten times diameter
which is usually less than 5 mm.
Outer Diameter; Outside Diameter.
See Outer Ring.
See Internal Race.
The outer part of a bearing that fits into the housing and contains the
internal raceway for the rolling elements.
Outer Ring Raceway
See Internal Race.
The portion of a cage shaped to hold the ball or roller. Also Ball Pocket;
An internal loading characteristic in a bearing which is independent of
any external radial and/or axial load carried by the bearing.
A shielded, sealed, or open bearing originally lubricated by the manufacturer.
Class or degree of precision of anti-friction roller bearings.
The ball or roller path; cut in the inner and outer ring in which the balls
or rollers ride. Also Guide Path; Race; Ball Path; Roller Path.
Inner Ring -- the outer dimension across the diameter from raceway
bottom to raceway bottom.
Outer Ring -- the inner dimension across the diameter from raceway
bottom to raceway bottom.
The radial internal clearance of a single row radial contact ball bearing
is the average outer ring race diameter, minus the average inner ring race
diameter, minus twice the ball diameter.
A load exerted perpendicular to the axis.
See Radial Clearance.
Radial Type Bearing
In general, a rolling element bearing primarily designed to support load
perpendicular to the axis. Also: Annular Bearing.
L10 of group of apparently identical bearings is the life in millions of
revolutions that 90% of the group will complete or exceed.
Relieved End Roller
Roller with slight modification of diameter at ends of outside surface
to reduce stress concentration at contacts between rollers and raceways.
See Ball Cage.
Riveted Type Ball Cage
A type of cage in which the two halves are riveted together around the
balls after the balls have been assembled in the rings.
Runout, of Assembled Bearing
Displacement of surface of bearing relative to fixed point when one raceway
is rotated with respect to other raceway.
A soft synthetic rubber washer with a steel core fixed in the outer ring
(in the seal groove) in contact with the inner ring to retain lubricant
and keep out contamination.
Self Aligning Ball Bearing
Spherical outside diameter ball bearing which can accommodate initial angular
misalignment between the outer ring and its mating spherical aligning ring
or housing seat.
A bearing that may be separated completely or partially into its component
See Ball Cage.
Amount of interference or clearance between bearing inside diameter and
shaft bearing seat outside diameter.
A metal formed washer attached to the outer ring and set so it rides close
to, but not contacting, the inner ring, to retain lubricant and prevent
The side of a ball race, also a surface in a bearing application or shaft
which axially positions a bearing and takes the thrust load.
Bearing with one row of rolling elements.
A removable ring used to axially position a bearing or outer ring in a
housing. Also used as a means of fastening a shield or seal in a bearing.
A solid ring type separator used in a radial or angular contact type bearings.
Sleeve or sleeves serving to space different bearings on same shaft or
different rows of rolling elements in multi-roll bearing.
Spherical Roller Bearing
Self-aligning, radial rolling bearing with convex rollers or concave rollers
as rolling elements. With convex rollers outer ring has spherical raceway,
with concave rollers inner ring has spherical raceway.
Bearing which conforms to the basic plan for boundary dimensions of metric
or inch dimensions.
A load exerted on a bearing not in motion.
A flat elongated rivet used in the cages of maximum capacity bearings.
Stay Rod Type Ball Cage
Type cage in which the two halves are held together with special stay rod
See Axial Load.
A bearing designed primarily for thrust loads.
Face of thrust bearing against which housing or shaft shoulder pushes.
The range between two limiting sizes as a means of specifying the degree
The amount a given bearing dimension may vary from specifications.
The difference between the upper and lower limits of a dimension or a specification.
A means of specifying the degree of accuracy.
Radial roller bearing with heavy section outer ring, intended to roll on
track, a.k.a. cam follower.
Wide Inner Ring Bearing
Bearing with inner ring extended on one or both sides in order to achieve
greater shaft support and permit addition of locking device and provide
additional space for sealing devices.
Axial slotted sleeve with cylindrical bore, tapered outside surface and
male screw thread at large end. Used for mounting and dismounting (by means
of nut) of bearing with tapered bore on cylindrical outside surface of
shaft. Also called push-type sleeve.