61930 bearing: complete specifications & equivalents
The 61930 is a ISO 15 radial bearing sized 150 x 210 x 28 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NSK |
| Bore diameter d | 150 mm |
| Outer diameter D | 210 mm |
| Width B | 28 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 93.5 kN |
| Basic static load rating C0 | 90.5 kN |
| Mass | 3010 g |
| Manufacturer designation | NSK 6930 |
| Standard | ISO 15 |
| Catalog version | NSK Rolling Bearings E1103 Part C |
| Last verified | 2026-09-24 |
Source: catalog reference (NSK Rolling Bearings E1103 Part C) · extracted 2026-09-24
Dimensions in inches & 61900-series range
| Bore d | 5.906 in |
|---|---|
| Outer diameter D | 8.268 in |
| Width B | 1.102 in |
| ISO bore code | 30 |
| Radial section height (D−d)/2 | 30 mm |
| Smallest bore in 61900-series | 10 mm |
| Largest outer diameter in 61900-series | 420 mm |
| Width range across 61900-series | 6–56 mm |
| Bore position in 61900-series (smallest first) | 27 of 37 |
| Bore above smallest 61900-series size | 140 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 61930 | ISO-INTERCHANGE | full Dimensions and internal design equivalent — standard interchange. | ISO 15 boundary-dimension interchange; ratings above are NSK E1103 values and differ by brand — verify per supplier. |
Interchange levels: full standard interchange · partial verify parameters · verify manual confirmation required. Links resolve to the equivalent model's specification page where available.
How the 61930 model number is decoded
In the 61900-series (ISO 15 diameter series 9) the last two digits encode the bore: 61930 carries bore code 30 = 150 mm. Outside diameter 210 mm and width 28 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 150 mm shaft, typical catalogue practice is a m6 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude.
Typical equipment & failure modes
Common applications
- textile machinery
- packaging machinery
- space-constrained gearboxes
- clutch and transmission assemblies
Known failure patterns
- contamination wear from dust and dirt ingress through the open arrangement
- lubricant starvation when no regreasing interval is maintained
- fretting corrosion on a loose shaft seat
- cage damage from operation beyond the limiting speed
Selection pitfalls — read before you substitute
- Mount this 150 mm bore bearing by heating the inner ring (induction heater, max 120 °C) — never drive it home through the outer ring or balls, that brinells the raceways.
- The 619xx thin section (30.0 mm section height at 150 mm bore) trades load capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.
- The open 61930 has no lubricant retention: grease escapes and contaminants migrate straight into the 150×210×28 mm raceway, so specify a sealed arrangement for dusty or washdown duty.
- Open bearings tolerate the highest speeds in the 61900-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 61930 units.
- A 150 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.
- The open 61930 needs external sealing and application-supplied lubrication; in the NSK catalogue the protected variants are separate order numbers with suffixes ZZ (shields), VV (non-contact rubber seals) and DDU (contact rubber seals).
- The 93.5/90.5 kN ratings, mass 3010 g here are NSK Rolling Bearings E1103 Part C catalogue figures for 6930; this seal/size combination has no counterpart in the SKF 17000 extract used elsewhere on this site, so the page rests on a single manufacturer source — internal geometry and ratings legitimately differ between brands, so re-verify before substituting in a rated drive.
Frequently asked questions
What are the dimensions of a 61930 bearing?
A 61930 deep-groove ball bearing has a 150 mm bore, 210 mm outer diameter and 28 mm width (5.906 × 8.268 × 1.102 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields.
How does the 61930 bore code work?
The last two digits of 61930 are bore code 30, giving 30 × 5 = 150 mm bore. The 210 mm outside diameter and 28 mm width follow the ISO 15 diameter series, not the bore code alone.
What does no suffix on 61930 mean?
A bare 61930 designation means open: no shields or seals, normal CN radial clearance and P0 normal tolerance unless further suffixes are ordered. The application must supply and retain the lubrication.
How does the 61900 compare with other series at the same 150 mm bore?
619 is a thin section one step above 618: 210×28 mm with a 30.0 mm radial section at 150 mm bore; a 6230 on the same bore is substantially larger and more heavily rated.
What is the NSK designation and catalogue data for 61930?
In the NSK Rolling Bearings catalogue (E1103 Part C) this size is listed as 6930 — the open (unsealed) execution, 150×210×28 mm per ISO 15. Quoted values: C 93.5 kN, C0 90.5 kN, mass 3010 g. The industry-neutral page spelling 61930 follows the seal-suffix convention used across this site, not NSK order-number spelling. Reference and limiting speeds are not tabulated in the E1103 dimension tables used here; consult NSK speed tables before high-speed service.
Reviewed & verified by the MPN Base engineering desk against source catalog NSK Rolling Bearings E1103 Part C on 2026-09-24. Read our editorial & correction policy.