# Tapered roller bearing

## Geometry

Tapered roller bearing, 302 and 303 series, bore up to 50 mm. Bore d, outside diameter D, overall width T, cone width B, cup width C and chamfers r (cone back) and r1 (cup back) are sourced and make the fit. detail = "full": the cone with its back rib, the cup and the tapered rollers at an angle between them. The 14 degree angle, roller size, rib and roller count are proportions for looks, not for design, and never change the fit dimensions; the cage is not drawn. detail = "simple": one solid ring d x D x T. Axis along Z, centred on the origin; cone back face at z = -T/2, cup back face at z = +T/2.

**For the fit:** the sourced dimensions below. **For looks only, not for design:** every other proportion named above.

## Source

NTN, *Ball and Roller Bearings*, CAT. No. 2203-3/E (2024), <https://www.ntnglobal.com/en/products/catalog/pdf/2203E.pdf>, PDF pages 165 to 167.

| Number | d | D | T | B | C |
|---|---|---|---|---|---|
| 30203 | 17 | 40 | 13.25 | 12 | 11 |
| 30204 | 20 | 47 | 15.25 | 14 | 12 |
| 30205 | 25 | 52 | 16.25 | 15 | 13 |
| 30206 | 30 | 62 | 17.25 | 16 | 14 |
| 30207 | 35 | 72 | 18.25 | 17 | 15 |
| 30208 | 40 | 80 | 19.75 | 18 | 16 |
| 30209 | 45 | 85 | 20.75 | 19 | 16 |
| 30210 | 50 | 90 | 21.75 | 20 | 17 |
| 30302 | 15 | 42 | 14.25 | 13 | 11 |
| 30303 | 17 | 47 | 15.25 | 14 | 12 |
| 30304 | 20 | 52 | 16.25 | 16 | 13 |
| 30305 | 25 | 62 | 18.25 | 17 | 15 |
| 30306 | 30 | 72 | 20.75 | 19 | 16 |
| 30307 | 35 | 80 | 22.75 | 21 | 18 |
| 30308 | 40 | 90 | 25.25 | 23 | 20 |
| 30309 | 45 | 100 | 27.25 | 25 | 22 |
| 30310 | 50 | 110 | 29.25 | 27 | 23 |

Maker names identify the source; this part isn't made by or affiliated with any maker.

Chamfers r and r1 are in `part.py` (`BEARINGS`), from the same tables. No tolerance class is stated yet.