71920 bearing: complete specifications & equivalents
The 71920 is a ISO 15 radial bearing sized 100 x 140 x 20 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | Generic ISO interchange (unbranded) |
| Bore diameter d | 100 mm |
| Outer diameter D | 140 mm |
| Width B | 20 mm |
| Seal / shield | open |
| Internal clearance | CN / C3 available |
| Tolerance class | P0 |
| Cage | brass |
| Operating temperature | -40 to +150 °C |
| Mass (geometry estimate) | 769 g |
| Standard | ISO 15 |
| Catalog version | iso15-ed4-geometry |
| Last verified | 2026-09-24 |
Source: ISO 15 boundary-dimensions standard · extracted 2026-09-24
Standard-interchange bearing: dimensions per ISO 15; CN clearance, P0 tolerance and a stamped-steel cage are catalogue defaults unless the supplier states otherwise, and mass is a geometry-derived estimate. Brand catalogue load ratings and limiting speeds for 71920 are being backfilled — use the inquiry form for certified values.
Dimensions in inches & 71900-series range
| Bore d | 3.937 in |
|---|---|
| Outer diameter D | 5.512 in |
| Width B | 0.787 in |
| ISO bore code | 20 |
| Radial section height (D−d)/2 | 20 mm |
| Smallest bore in 71900-series | 20 mm |
| Largest outer diameter in 71900-series | 140 mm |
| Width range across 71900-series | 9–20 mm |
| Bore position in 71900-series (smallest first) | 17 of 17 |
| Bore above smallest 71900-series size | 80 mm |
Cross references & equivalents
No verified interchange data yet. Send an inquiry and our team will confirm equivalents manually.
How the 71920 model number is decoded
In the 71900-series (ISO 15 diameter series 9) the last two digits encode the bore: 71920 carries bore code 20 = 100 mm. Outside diameter 140 mm and width 20 mm come from the ISO 15 boundary-dimensions general plan, shared with the 61920 deep-groove envelope. The '7' prefix marks a single-row angular-contact design with an asymmetric raceway and a nominal 40° contact angle (suffix C); a higher-angle variant carries more axial load, a 25° (E / A5) variant runs faster. For combined radial and axial load with a rotating inner ring on a 100 mm shaft, specify a k5 shaft seat with an H7 housing bore — verify against the load direction and magnitude, and pair two units (DB or DF) for bidirectional thrust.
Typical equipment & failure modes
Common applications
- robotics joint arms
- precision rotary tables
- medical and lab spindles
- clutch and idler shafts
Known failure patterns
- cage fracture from operation beyond the limiting speed with inadequate lubricant
- fretting corrosion on a loose shaft seat that lets the inner ring creep
- false brinelling from vibration while the shaft is stationary
- edge loading and early spalling from shaft deflection or housing misalignment
Selection pitfalls — read before you substitute
- Mount this 100 mm bore angular-contact pair by heating the inner rings (induction heater, max 120 °C) and clocking both faces; never drive a pair home through the outer rings.
- The 719xx thin section (20.0 mm section height at 100 mm bore) trades capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.
- With a 20.0 mm radial section on a 100 mm bore, the 71920 ring has little stiffness of its own: it copies the seat geometry, so grind the 100 mm shaft in one setup and check roundness — an out-of-round journal distorts the thin inner ring and reappears as vibration at the 140 mm housing.
- The 40° contact angle (suffix C) raises axial capacity but lowers speed versus a 25° (E / A5) variant; for high-speed spindles specify the 25° version, for heavy thrust specify 40°.
- Angular-contact 71920 tolerates only minutes of misalignment; a deflected shaft or a tilted housing face edge-loads the asymmetric raceway and spalls it early — align the seats to better than 0.001 radian.
Frequently asked questions
What are the dimensions of a 71920 angular-contact bearing?
A 71920 single-row angular-contact ball bearing has a 100 mm bore, 140 mm outer diameter and 20 mm width (3.937 × 5.512 × 0.787 in), per ISO 15 boundary dimensions. It is an open bearing with a nominal 40° contact angle. Geometry-based estimated mass is about 769 g for a brass-cage unit; catalogue masses vary with cage and ball complement.
How does the 71920 bore code work?
The last two digits of 71920 are bore code 20, giving 20 × 5 = 100 mm bore. The 140 mm outside diameter and 20 mm width follow the ISO 15 diameter series, shared with the 61920 deep-groove envelope.
What is the contact angle of 71920?
The nominal contact angle is 40° (suffix C): a higher angle carries more axial load but limits speed. A 25° (suffix E or A5) variant runs faster and is preferred for high-speed spindles; a 15° (suffix C7) version exists for very-high-speed duty. Confirm the angle and ball complement in the supplier catalogue.
Can a single 71920 take axial load in both directions?
No. A single-row angular-contact bearing carries axial load in one direction only. For bidirectional thrust, mount a matched pair — DB (back-to-back) for a rigid, moment-resisting arrangement with preload class light (L) for speed or heavy (H) for stiffness, DF (face-to-face) for thermal expansion tolerance, or DT (tandem) to share one-direction load.
How fast can a 71920 run?
Thin-section angular-contact bearings reach high speeds because the 20.0 mm section keeps the ball set light, but the practical limit is set by the lubricant and the precision of the 100 mm seat rather than the geometry alone; a 25° (E/A5) contact-angle variant and a light (L) preload class run faster than a 40° heavy-preloaded pair. Confirm the limiting speed in the supplier catalogue.
Reviewed & verified by the MPN Base engineering desk against source catalog iso15-ed4-geometry on 2026-09-24. Read our editorial & correction policy.