Start with the bearing structure, then explore the original subtypes and filter actual records by brand, dimensions and technical attributes.
Save a six-page English reference with a classification chart, eight common rolling-bearing families, real catalogue examples, application checks, plain and specialist bearing forms, and a model-search checklist.
Scope: an illustrated introduction, not an exhaustive catalogue, all-size chart, manufacturer manual or CAD drawing. The named models are construction examples, not machine-fitment recommendations.
Download PDF guideStart by deciding what is being classified. Rolling versus plain describes the support principle; ball versus roller describes the rolling element; radial versus thrust describes the main load direction. These are different questions, so the number of bearing types changes with the level of the classification.
Rolling elements between the supporting surfaces
A sliding interface; its material and lubrication system matter
This is an orientation map, not an exhaustive catalogue of specialist systems. Load direction is a second classification axis:
| Rolling element | Mainly radial family | Mainly axial family |
|---|---|---|
| Balls | Radial ball bearings | Thrust ball bearings |
| Rollers | Radial roller bearings | Thrust roller bearings |
A radial family can have specified axial capability; the exact design decides. “Thrust” is not a third rolling-element shape alongside ball and roller.
For a basic mechanical comparison, use rolling bearings and plain (sliding) bearings. Within rolling bearings alone, the two element groups are ball and roller. Do not confuse these two different divisions.
Ball, roller and plain bearings are a useful three-group introduction: the first two split the rolling branch, while plain bearings form the sliding branch. This is a teaching arrangement, not a rule that every specialist bearing system fits only three boxes.
Four examples are deep groove ball, angular contact ball, cylindrical roller and tapered roller bearings. If the question instead asks for four roller shapes, the answer is cylindrical, needle, tapered and spherical. The classification chart keeps those meanings separate.
A short five-example list can use deep groove ball, angular contact ball, cylindrical roller, tapered roller and spherical roller bearings. It leaves out other important families; five is the length of that list, not the total number of bearing designs.
The illustrated list below contains four ball-bearing families and four radial roller-bearing families. Thrust roller bearings, plain bearings, linear guides and mounted units still exist outside that eight-example list.
These are construction examples, not model recommendations for your machine. The pictures belong to the named example records; exact variants can look different. Use the family page and complete product record to check the specification.
Balls in deep ring grooves
Balls with an inclined contact line
Two ball rows; common spherical outer raceway
Balls between shaft and housing washers
Rollers with parallel sides
Long, slender rollers
Conical rollers; cone and cup
Barrel-shaped rollers; self-aligning raceway
These original sketches show rolling-element profiles, not complete bearing sections or manufacturing drawings. Roller shape is a useful clue; it does not by itself prove the exact model, load rating or installed arrangement.
For an exercise that asks you to draw two complete roller-bearing sections, use the exact construction and its section drawing. These element-profile sketches are not a substitute for a full bearing drawing.
“Friction bearing” is often used for a plain bearing; it does not mean every plain bearing runs dry. Likewise, “antifriction bearing” commonly means a rolling-element bearing, not a bearing with zero friction.
| Form | Support principle | Selection boundary |
|---|---|---|
| Journal bearing / sleeve bush | Sliding support around a shaft; commonly a radial-support form. | Check material, lubrication, running clearance and shaft surface. |
| Thrust washer / plain thrust bearing | Sliding axial support at a shaft face or shoulder. | Do not treat a radial bush dimension as a complete thrust-bearing specification. |
| Spherical plain bearing / rod end | A spherical sliding interface permits articulation; a rod end also provides its mounting shank. | Check articulation, sliding pair, load direction and any thread specification. |
In a fluid-film bearing, liquid or gas separates the supporting surfaces under the specified operating conditions. A hydrodynamic design develops its supporting film through relative motion; an externally pressurized design needs a pressure supply. An air bearing is therefore not an ordinary rolling bearing with air substituted for its grease.
A magnetic bearing supports the shaft through magnetic forces. Its support and control system must be considered as a system, not identified from the d×D×B dimensions of a conventional rolling bearing. This guide does not supply validated models or operating limits for these specialist systems.
A mounted unit combines a bearing with a housing; a housing alone is not another rolling-element shape. Linear bearings describe guided translation, and cannot be selected by a rotary bearing size alone.
Technical basis: NSK Bearing ABCs and the named product-family references. Diagrams, classification explanation and lookup sequence are original BearingScope content. Model examples are existing catalogue records, not application approvals.
A bearing supports and guides relative movement between machine parts. A rolling bearing uses balls or rollers; a plain bearing uses sliding surfaces. A linear guide supports translation rather than ordinary shaft rotation. These names describe different structures, not different quality grades.
In a typical radial rolling bearing, balls or rollers run between the raceways of an inner ring and an outer ring. The rolling elements carry load between the rings as relative rotation occurs. A cage, when fitted, keeps the rolling elements separated. Ball bearings use balls; roller bearings use cylindrical, tapered, needle or spherical rollers according to the design. The rolling-element shape and raceway arrangement determine the family, not the brand name.
This is a structural explanation, not a claim of friction-free motion or a complete parts list for every bearing. Some assemblies use prepared shaft surfaces or separate washers instead of a conventional pair of radial rings.
Radial force acts across the shaft axis. Axial or thrust force acts along it. A tilting moment tends to turn the supported member out of alignment. A family name helps identify the load path, but the exact design and arrangement determine what is permitted.
A thrust bearing supports force along the shaft axis. In a rolling thrust design, balls or rollers transmit that force between the specified raceway surfaces while allowing relative rotation. A single-direction thrust ball bearing uses a shaft washer, a housing washer and a ball-and-cage assembly; a double-direction design has two ball-and-cage assemblies and an intermediate shaft washer. Roller thrust designs require their own washer and roller identification.
Single-direction and double-direction describe axial support, not clockwise versus anticlockwise shaft rotation. Thrust ball bearings do not carry radial load; do not extend that rule indiscriminately to every roller thrust construction.
| Need to identify | Start with | Important distinction |
|---|---|---|
| Radial ball bearing | Deep groove ball bearings | Not every ball bearing is a deep groove design. |
| Combined load / contact angle | Angular contact ball bearings | Single-row direction and pair arrangement matter. |
| Axial ball bearing | Thrust ball bearings | Axial support does not provide radial guidance. |
| Radial roller bearing | Cylindrical roller bearings | Ribs determine axial location or displacement. |
| Combined load / cup and cone | Tapered roller bearings | Keep both component identities and assembly width. |
| Self-aligning heavy-load design | Spherical roller bearings | Do not confuse rollers with self-aligning ball designs. |
| Compact roller section | Needle roller bearings | Check which adjacent surfaces form the raceways. |
| Sliding bush or sleeve | Plain bearings | Material and sliding duty govern the checks. |
| Pillow block / flange unit | Mounted bearing units | Identify the housing, insert and locking method. |
| Translation on a rail or shaft | Linear bearings and guides | Rail/carriage geometry is not a rotary d×D×B envelope. |
Use the structure-specific pages for deep groove, angular contact, self-aligning and thrust ball bearings. Loose bearing balls are components, not a complete bearing: a ball diameter alone cannot establish the bearing model or its load rating.
Technical reference basis: NTN Rolling Bearings and Bearing Structure and Types; JTEKT Thrust Ball Bearings. This is a family-identification guide, not an application approval.
Each original catalogue subtype belongs to one structural group below. Counts refer to loaded records, not manufacturer catalogue completeness. Materials and special features remain separate filters.
A complete insert-and-housing assembly, rather than a bare bearing.
4,430 records · 11 subtypes →Units & componentsSplit or one-piece housings support a separately specified bearing.
3,762 records · 13 subtypes →Units & componentsMounting and sealing components have their own geometry and mating requirements.
5,160 records · 59 subtypes →Plain & articulatedSliding spherical surfaces accommodate articulation; rod ends add a threaded or shanked mounting.
2,282 records · 26 subtypes →Linear motionLinear ball bushings and profiled guides are distinct systems, not interchangeable by shaft diameter alone.
1,630 records · 24 subtypes →Roller bearingsTrack-running bearings use reinforced outer rings; stud and yoke mounting arrangements differ.
2,075 records · 17 subtypes →Roller bearingsAlternating roller orientations can support radial, axial and moment loads in a compact arrangement.
682 records · 4 subtypes →Special arrangementsLarge ring bearings support combined loads and moments, often with mounting holes or gearing.
1,594 records · 15 subtypes →Roller bearingsRollers carry predominantly axial load; cylindrical, needle and spherical thrust designs have different alignment capability.
1,441 records · 24 subtypes →Ball bearingsThrust ball bearings carry axial loads; a separate radial bearing is usually required.
1,623 records · 10 subtypes →Roller bearingsCone and cup geometry determines the assembly; single-row bearings normally work in opposed arrangements.
19,210 records · 32 subtypes →Roller bearingsSelf-aligning roller designs support substantial radial load and, depending on design, axial load.
9,021 records · 14 subtypes →Roller bearingsSmall-diameter rollers provide a compact radial section; some designs run directly on a prepared shaft.
5,438 records · 27 subtypes →Roller bearingsRib arrangement determines axial location: NU, N, NJ and NUP are not functionally identical.
8,728 records · 37 subtypes →Ball bearingsTwo ball rows and a spherical outer raceway accommodate limited shaft-to-housing misalignment.
910 records · 5 subtypes →Ball bearingsContact angle, row count and pairing determine axial load direction and stiffness.
13,391 records · 59 subtypes →Units & componentsInsert bearings commonly have extended inner rings and shaft-locking features for mounted units.
653 records · 1 subtypes →Ball bearingsA versatile radial bearing family with some axial-load capability; single and double rows differ.
13,851 records · 32 subtypes →Plain & articulatedSliding-contact designs may be metallic, polymeric or composite; lubrication and PV limits are material-specific.
1,155 records · 17 subtypes →Special arrangementsOverrunning or indexing devices transmit torque in one direction; they may need separate support bearings.
41 records · 1 subtypes →Ball bearingsLess common ball-bearing descriptions are retained without forcing them into a misleading standard family.
1,023 records · 8 subtypes →Roller bearingsSpecial roller-bearing forms require their own geometry and mounting checks.
1,042 records · 13 subtypes →Units & componentsRemaining catalogue descriptions are preserved here, including specialist components that are not standalone bearings.
4,349 records · 47 subtypes →No family matches this text. Clear the search to see all groups.
Miniature, thin-section, stainless and ceramic describe additional selection needs rather than one universal bearing structure. Choose the structure, then verify the dimensional section and recorded material. Air and magnetic bearings require system-level design and are not represented as ordinary rolling-bearing substitutes.
Small size does not remove the need to specify load, closure and mounting tolerances.
Read and apply →A small cross section is a design characteristic, not a statement that every thin bearing is interchangeable.
Read and apply →A flange on a miniature bearing ring is not the same component as a two-bolt or four-bolt flanged housing.
Read and apply →Separate rolling-element material from ring material and the complete bearing construction.
Read and apply →A stainless label does not establish compatibility with every chemical, washdown or marine exposure.
Read and apply →Air-film systems are not ordinary rolling bearings with an interchangeable part number.
Read and apply →A magnetic bearing is part of a rotor support and control system, not a simple size replacement for a ball bearing.
Read and apply →A journal-bearing system depends on the sliding geometry and lubricant film, not a rolling-bearing L10 calculation alone.
Read and apply →Manufacturer terminology is retained in the product records. Technical reference basis: JTEKT Basic Bearing Knowledge (boundary dimensions, tolerance classes and lubrication); NSK Bearing ABCs (lubrication, designations and clearance); NTN technical FAQs (closure codes and component interchange); SKF rolling-bearing selection and maintenance references.
Selection workflows and catalogue grouping are BearingScope editorial aids. Verify the current drawing and application requirements before using a candidate. Missing database information is not converted into an assumed match.