61907-NSK bearing: complete specifications & equivalents
The 61907-NSK is a ISO 15 radial bearing sized 35 x 55 x 10 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NSK |
| Bore diameter d | 35 mm |
| Outer diameter D | 55 mm |
| Width B | 10 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 11.6 kN |
| Basic static load rating C0 | 7.25 kN |
| Operating temperature | -40 to +150 °C |
| Mass | 75 g |
| Manufacturer designation | NSK 6907 |
| 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 | 1.378 in |
|---|---|
| Outer diameter D | 2.165 in |
| Width B | 0.394 in |
| ISO bore code | 07 |
| Radial section height (D−d)/2 | 10 mm |
| Smallest bore in 61900-series | 3 mm |
| Largest outer diameter in 61900-series | 1120 mm |
| Width range across 61900-series | 3–118 mm |
| Bore position in 61900-series (smallest first) | 15 of 63 |
| Bore above smallest 61900-series size | 32 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 61907-FAG | FAG | full Dimensions and internal design equivalent — standard interchange. | Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 61907-2RS-FAG | FAG | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 61907-ZZ-FAG | FAG | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 61907-NTN | NTN | full Dimensions and internal design equivalent — standard interchange. | Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 61907-2RS-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 61907-RSR-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 61907-ZZ-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 61907 | SKF | full Dimensions and internal design equivalent — standard interchange. | Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 61907-2RS | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| 61907-RSR | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
| W61907-2RS | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 35×55×10 mm envelope per ISO 15; seal variant and load ratings may differ — confirm sealing and rating before substituting. |
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 61907-NSK model number is decoded
In the 61900-series (diameter series 9 of ISO 15) the last two digits encode the bore: 61907 carries bore code 07 = 35 mm. Outside diameter 55 mm and width 10 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 35 mm shaft, typical catalogue practice is a k5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. In the NSK catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (steel shields), VV (non-contact rubber seals) and DDU (contact rubber seals).
Typical equipment & failure modes
Common applications
- space-constrained gearboxes
- clutch and transmission assemblies
- robotics and automation joints
- lay shafts and idler shafts
Known failure patterns
- contamination wear from dust and dirt ingress through the open arrangement
- lubricant starvation when no regreasing interval is maintained
- cage damage from operation beyond the limiting speed
- electrical pitting in VFD-driven motors without grounding protection
Selection pitfalls — read before you substitute
- Sizes around 35 mm bore are normally pressed on cold with a sleeve against the inner-ring face; the press force must never route through the outer ring or the balls of 61907-NSK.
- The 619xx thin section at 35 mm bore (10.0 mm section height) cannot shrug off the misalignment a standard section tolerates; keep the housing bores round and aligned, or edge contact will spall the raceways early.
- The open 61907-NSK has no lubricant retention: grease escapes and contaminants migrate straight into the 35×55×10 mm raceway, so specify a sealed arrangement for dusty or washdown duty.
- Storage matters for open bearings: 61907-NSK leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.
- The housing bore for the 55 mm OD should be round within IT7; an oval bore pinches the outer ring of 61907-NSK and shows up later as two-point loaded raceway wear.
- Do not quieten a noisy bearing by preloading it: the 61900-series is a deep-groove design, not angular-contact; axial preload raises temperature and shortens grease life.
- The open 61907 has no integral sealing; in the NSK E1103 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), VV (non-contact rubber seals) and DDU (contact rubber seals). NSK does not offer a low-torque contact seal equivalent to NTN's LLH in this catalogue — for high-speed sealed duty specify the VV non-contact seal and an external housing labyrinth.
- The 35 mm bore puts 61907 in NSK's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty. NSK's VV non-contact seal is the high-speed choice here — DDU contact seal costs roughly 30–40% of the open-bearing speed ceiling.
- NSK rates 61907 at 11.6 kN dynamic (C) and 7.25 kN static (C0); this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.
- At 75 g, 61907 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.
- The 35×55×10 mm envelope of 61907 gives a D/d ratio of 1.57 and 10.0 mm radial section height — this NSK thin section saves space but is sensitive to misalignment and shock; confirm the housing stays round within IT7 and the shaft does not deflect past the raceway contact angle under load.
- The 11.6/7.25 kN load ratings, mass 75 g here are NSK Rolling Bearings E1103 Part C catalogue figures for 6907 on the 35×55×10 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61907 in a rated drive. NSK does not tabulate reference or limiting speeds in the E1103 Part C dimension tables used for this page — consult NSK's separate speed-rating tables before high-speed service.
- Keep NSK bearings in the original packaging until fitting: the wrapper carries the production lot, and the unopened shelf life of greased sealed units is typically quoted at three to five years in dry, vibration-free storage.
- NSK supplies its sealed units pre-greased for general duty between roughly -10 and +110 °C; low-temperature, food-grade and high-temperature fills are special executions — ask at order time, because DDU/VV units are not designed to be opened and repacked.
Frequently asked questions
What are the dimensions of a 61907-NSK bearing?
A 61907-NSK deep-groove ball bearing has a 35 mm bore, 55 mm outer diameter and 10 mm width (1.378 × 2.165 × 0.394 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields.
What does no suffix on 61907 mean?
A bare 61907 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 35 mm bore?
619 is a thin section one step above 618: 55×10 mm with a 10.0 mm radial section at 35 mm bore; a 6207 on the same bore is substantially larger and more heavily rated.
What is the NSK order number for an open 61907?
NSK lists the open 61907 under the bare designation 6907; protected versions use suffixes ZZ (steel shields), VV (non-contact rubber seals) and DDU (contact rubber seals) on the same 35 mm bore envelope.
Does NSK offer 61907 with C3 clearance?
NSK lists C3 (and C4) internal-clearance options for most deep-groove sizes under the same base designation; the clearance is fixed at manufacture, so specify it at order time rather than planning to adjust later.
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.