A4050 bearing dimensions & suffix variants
Look up recorded dimensions for designations beginning with A4050. The table retains complete manufacturer designations so special suffixes and different dimensional variants remain visible.
On this page6 sections ⌄
Find by measured dimensions
Enter bore d, outside diameter D and width B. Use decimals or inch fractions such as 1/2 or 1 1/4.
TIMKEN A4050 — individual cone dimensions
TIMKEN A4050 is an individual tapered-roller cone: the inner ring, rollers and cage, not the complete cone-and-cup bearing. The manufacturer lists bore d = 12.7 mm (1/2 in) and inner-ring width B = 10.988 mm (0.4326 in).
| Measurement | Symbol | Metric | Inches |
|---|---|---|---|
| Bore (d) | d | 12.7 mm | 1/2 in |
| Inner Ring Width (B) | B | 10.988 mm | 0.4326 in |
| Effective Center Location | Not specified | -2.5 mm | -0.1 in |
| Shaft Backing Shoulder Diameter - Frontface (da) | da | 17 mm | 0.67 in |
| Shaft Backing Shoulder Diameter - Backface (db) | db | 18.5 mm | 0.73 in |
| Cage Location rel. to BF (Aa) | Aa | 0 mm | 0 in |
| Cage Location rel. to FF (Ab) | Ab | 1.8 mm | 0.07 in |
Use the component number correctly
- The bore identifies the shaft-side nominal opening. B measures this cone only; it is not the assembled bearing width T. This single-cone record does not establish an outside diameter D or a matching cup.
- Preserve the full component number and its suffix. A shared prefix, similar ring size or a related-products suggestion does not approve a cone/cup combination or a cross-brand replacement.
- For a complete bearing, check both component markings and the manufacturer’s assembled d×D×T record. B+C is not a valid way to calculate T. A seal, axle rating, vehicle application and tightening procedure need their own evidence.
- Optional measurements with inconsistent printed metric and inch values are omitted from this supplement: Max Shaft Fillet Radius. Verify the manufacturer drawing before using these particular limits.
Factual reference: Timken official individual-component catalogue; source snapshot 2026-10-02. Original interpretation by BearingScope. These measurements do not certify a complete assembly, fit or interchange.
A4050 dimensions and recorded technical data
Use the named dimensions for each complete record below. A generic d×D×B answer is not asserted where the base record is missing, dimension symbols are unverified, or the product uses a different geometry such as a housing or thrust assembly. Suffix records are not substituted for a missing base specification.
The numeric series boundary is preserved: a longer number is not included merely because its first digits match. 5 recorded variants are listed. A dash means the value is missing, not zero.
No recorded variant matches these filters. Clear a filter to see other records; no substitute has been inferred.
| Brand / full designation | Named dimensions (mm / in) | Dynamic C (kN) | Static C0 (kN) | Reference speed (rpm) | Limiting speed (rpm) | Mass (kg / g) |
|---|---|---|---|---|---|---|
| TIMKENA4050-90012Tapered roller bearing |
| 15.6 kN | 11.5 kN | — | — | 0.05 kg50 g |
| TIMKENA4050-90068Tapered roller bearing |
| 15.6 kN | 11.5 kN | — | — | 0.05 kg50 g |
| TIMKENA4050 / A4138Tapered roller bearing |
| 15.6 kN | 11.5 kN | — | — | 0.05 kg50 g |
| TIMKENA4050 / A4138BTapered roller bearing |
| 15.6 kN | 11.5 kN | — | — | 0.05 kg50 g |
| KOYOA4050/138Tapered roller bearing |
| 15.7 kN | 11.9 kN | — | 12000 rpmLimiting Speeds(Grease Lub.): 12000 min-1Limiting Speeds(Oil Lub.): 17000 min-1 | 0.055 kg55 g |
Compare recorded seals, clearance, precision and materials
Manufacturer wording is retained. A missing property is not inferred from another brand or a similar suffix.
| Brand / designation | Closure | Original precision | Clearance | Cage | Material | Lubricant |
|---|---|---|---|---|---|---|
| TIMKEN A4050-90012 | Open | ABMA Class 0 | Not recorded | Steel cage | Not recorded | Not recorded |
| TIMKEN A4050-90068 | Open | ABMA Class 0 | Not recorded | Steel cage | Not recorded | Not recorded |
| TIMKEN A4050 / A4138 | Open | ABMA Class 2 | Not recorded | Steel cage | Not recorded | Not recorded |
| TIMKEN A4050 / A4138B | Open | ABMA Class 2 | Not recorded | Steel cage | Not recorded | Not recorded |
| KOYO A4050/138 | Not recorded | Not recorded | Not recorded | Not recorded | Not recorded | Not recorded |
How to compare these values
- Use the displayed dimension names and original symbols. Housing length L, height H2 and flange width are not bearing outside diameter D. A catalogue width with an unverified symbol must not be assumed to be inner-ring width B or assembly width T. Open the product record for mounting dimensions and geometry.
- Inch values are calculated from the recorded millimetres using 25.4 mm per inch, rounded to six decimal places. They do not change a metric bearing into an inch-series bearing. Gram values are converted from the recorded mass in kilograms.
- C and C0 describe different rating conditions. They are not a single safe working-load limit and cannot replace an application load calculation.
- Reference and limiting speeds are separate catalogue values. The source grease/oil context is shown where recorded. Lubricant, seals, loads, fit, clearance and cooling affect the usable operating speed.
- A common base number does not prove equivalent seals, clearance, precision, material or interchangeability. Open the full designation for these fields.
Related prefix matches — other model numbers may appear
These discovery results can contain a longer number or a different component. They are not specifications for the requested exact model. Open the complete product to inspect its original geometry.
A4050/138
Tapered roller bearing
View full technical record →TIMKENA4050-90012
Tapered roller bearing
View full technical record →TIMKENA4050-90068
Tapered roller bearing
View full technical record →TIMKENA4050 / A4138
Tapered roller bearing
View full technical record →TIMKENA4050 / A4138B
Tapered roller bearing
View full technical record →Check the drawing before substituting
Nominal dimensions are not shaft-fit tolerances. Different variants can add grooves, flanges, wider rings or assembly components. When the table has different dimensions, the complete designation—not the shared prefix—controls.
Reference basis & data limits
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.