30204 bearing: complete specifications & equivalents
The 30204 is a ISO 355 radial bearing sized 20 x 47 x 15.25 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | SKF |
| Bore diameter d | 20 mm |
| Outer diameter D | 47 mm |
| Width B | 15.25 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel, stamped ribbon (J-type) |
| Basic dynamic load rating C | 34.1 kN |
| Basic static load rating C0 | 28 kN |
| Fatigue load limit Pu | 3 kN |
| Reference speed (thermal) | 12000 rpm |
| Limiting speed (mechanical) | 15000 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 120 g |
| Manufacturer designation | SKF 30204 |
| Standard | ISO 355 |
| Catalog version | SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 8.1 metric single-row TRB |
| Last verified | 2026-09-26 |
Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 8.1 metric single-row TRB) · extracted 2026-09-26
Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 8.1 metric single-row TRB); SKF® and SKF Explorer® are trademarks of AB SKF, used here for identification only — mpnbase is not an authorized SKF distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at skf.com.
Dimensions in inches & 30200-series range
| Bore d | 0.787 in |
|---|---|
| Outer diameter D | 1.85 in |
| Width B | 0.6 in |
| ISO bore code | 04 |
| Radial section height (D−d)/2 | 13.5 mm |
| Smallest bore in 30200-series | 15 mm |
| Largest outer diameter in 30200-series | 580 mm |
| Width range across 30200-series | 11.75–104 mm |
| Bore position in 30200-series (smallest first) | 3 of 37 |
| Bore above smallest 30200-series size | 5 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 30204 | ISO 15 | full Dimensions and internal design equivalent — standard interchange. | ISO 15 boundary-dimension envelope; standard interchange — confirm clearance class and precision with the supplier. |
| 30204-NTN | NTN | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 20×47×15.25 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application 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 30204 model number is decoded
For a 20 mm shaft carrying combined load, SKF lists 30204 under catalogue execution SKF 30204: one open single-row tapered roller bearing in the standard section of the 30200 family.Reading the designation: the leading 3 marks a single-row tapered roller bearing, the 0 is the ISO 355 diameter/width series (standard section), and the last two digits encode the 20 mm bore; the 47 mm OD and 15.25 mm width follow the ISO 355 general plan. SKF lists the plain number as the basic execution; letter suffixes such as B denote a steeper contact angle and are different order numbers. Selection arithmetic: the C0/C ratio is about 0.82 (static 28 kN against dynamic 34.1 kN), typical of a tapered roller sized for axial capacity, and the 3 kN fatigue load limit Pu is the equivalent-load floor used in the life calculation. Mounting practice for 30204: the rotating cone takes the interference fit (k5 on a 20 mm shaft), the cup slides for axial location, and reversing-thrust duty demands a paired O/X set rather than one bearing.
Typical equipment & failure modes
Common applications
- small automotive wheel hubs and trailer axles
- light-duty gearbox input/output shafts
- electric-motor pinion shafts
- steering knuckles and small differentials
Known failure patterns
- cup or cone misalignment when the separable rings are not seated square during mounting
- loose cup rotation in the housing when the specified press fit is not achieved
- roller large-end smearing against the cone rib after EP lubricant film failure
- false brinelling on idle paired sets exposed to machine vibration
- pressed-steel cage wear or fracture after prolonged running above the limiting speed
- electrical pitting on VFD-driven shafts without grounding protection
Selection pitfalls — read before you substitute
- At a 20 mm bore the thin cone and cup are easily distorted by an over-tight shaft nut; check seat runout (target Ra ≤ 0.8 µm) and torque the locknut progressively — a pinched 30204 shows up as gearbox vibration long before it fails.
- The 302 series at 20 mm bore (47×15.25 mm) is the standard tapered-roller envelope; stepping to a 32204 or 32304 changes OD, width and heat generation — it is not a drop-in swap when the housing and speed are fixed.
- Do not mix brands or executions inside one 30204 pair — matched sets are ground for a specific setting, and pairing a SKF basic unit with a different suffix variant will not share the setting evenly.
- A single 30204 cannot locate the shaft axially in both directions; mounting it singly on a reversing-thrust shaft leaves one direction uncontrolled — always use an O or X matched pair for bidirectional location.
- Shaft and housing fillets must clear the bearing chamfer so the 15.25 mm-wide cup seats square; use an undercut or withdrawal groove rather than an oversized radius that locks on the ring face.
- The 34.1/28 kN ratings are SKF catalogue 17000 values for the basic execution; SKF can revise internal geometry without changing the order number, so keep the catalogue version (PUB BU/P1 17000/1 EN, 2018) with the specification and re-verify for critical drives.
- SKF lists several executions of 30204 (basic, B steeper angle, Q/J2 clearance variants); they are not interchangeable order numbers — quote the full SKF 30204 designation when purchasing and match the execution to the mounting arrangement.
Frequently asked questions
What are the dimensions and catalogue data of 30204?
The SKF 30204 is a single-row tapered roller bearing with 20 mm bore, 47 mm outer diameter and 15.25 mm width (0.787 × 1.85 × 0.6 in) per ISO 355. From SKF catalogue PUB BU/P1 17000: basic dynamic load rating C 34.1 kN, C0 28 kN, fatigue load limit Pu 3 kN, reference speed 12,000 r/min, limiting speed 15,000 r/min, mass about 120 g. It is an open, separable bearing with a pressed-steel cage.
How does the 30204 bore code work?
The last two digits of 30204 are bore code 04, so 04 × 5 = 20 mm bore. The 47 mm OD and 15.25 mm width come from the ISO 355 dimension-series plan, shared with other tapered bearings of the same code.
What do the 30204 series and basic execution designations mean?
The leading 3 marks a single-row tapered roller bearing; the second digit 0 is the ISO 355 series (standard section). The SKF catalogue lists the ISO 355 dimension-series code after the bare number. A steeper-contact-angle variant (B suffix) is a different order number and is not interchangeable with the basic execution.
Can a single 30204 take axial load in both directions?
No — one single-row tapered roller bearing reacts thrust in one direction only, and under radial load its contact angle induces an axial force. Use two bearings as a matched pair: O (back-to-back) for a rigid, moment-resisting arrangement, X (face-to-face) where thermal expansion must be tolerated, or tandem where one-direction thrust is shared.
How does 30204 compare with a ball bearing of the same bore?
A tapered roller bearing has line contact and a steep contact angle: much higher combined axial-plus-radial capacity and shock resistance than a ball bearing of the same bore, at the cost of speed, one-direction thrust, mandatory pairing for reversing loads and a minimum axial load requirement. A ball bearing cannot be dropped into a combined-load 30204 position and vice versa — verify load direction, Fa/Fr ratio and speed before substituting.
Reviewed & verified by the MPN Base engineering desk against source catalog SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 8.1 metric single-row TRB on 2026-09-26. Read our editorial & correction policy.