6400 Series Bearings
The heavy series and the largest envelope here: at the same bore a 6400 is bigger across and wider than anything else in this library. A 6404 is 72 mm across on a 20 mm bore, against 47 mm for the 6204.
Heavy serieswhere it sits and what it trades away
The step from medium to heavy is the biggest single step on the ladder. On a 20 mm shaft the outside diameter runs 32 (61804), 37 (61904), 42 (6004 and 16004), 47 (6204), 52 (6304) and 72 mm (6404): light to medium adds 5 mm, and medium to heavy adds 20 mm on its own. That is what "heavy" means in a designation — not a heavier bearing of the same size, but a substantially larger housing built around the same shaft.
It is also the only series here that does not start at a 10 mm bore. The 6400 series begins at 6403, a 17 mm bore — there is no 6400, 6401 or 6402 — and runs to 6420 at a 100 mm bore, 250 mm outside diameter and 58 mm wide. That is 18 of the 21 bore codes tabulated here, and the largest bearing in this database by every measure. The top four sizes carry a 4 mm minimum chamfer, the largest value the ISO 15 plan uses.
What all that size buys is load capacity and shaft stiffness, and the price is the housing — which at this end of the ladder is no longer a rounding error. So the heavy series is the right answer where the shaft diameter is fixed, the load is genuinely heavy, and the housing can be built around the bearing. It is the wrong answer in a tight design that has already run out of room: past a point, changing bearing type serves better than going up another diameter series. That is general engineering practice rather than anything ISO 15 decides — the standard fixes the dimensions, not the choice.
Every designation in the table below links to its own page with the ISO 15 dimensions, the bore-code arithmetic, the ISO 5753-1 clearance ranges for its bore, and the same-bore comparison against every other series.
All 18 designationsISO 15 boundary dimensions, mm
| Designation | Bore code | d | D | B | r s min | Section (D − d)/2 |
|---|---|---|---|---|---|---|
| 6403 | 03 | 17 | 62 | 17 | 1.1 | 22.5 |
| 6404 | 04 | 20 | 72 | 19 | 1.1 | 26 |
| 6405 | 05 | 25 | 80 | 21 | 1.5 | 27.5 |
| 6406 | 06 | 30 | 90 | 23 | 1.5 | 30 |
| 6407 | 07 | 35 | 100 | 25 | 1.5 | 32.5 |
| 6408 | 08 | 40 | 110 | 27 | 2 | 35 |
| 6409 | 09 | 45 | 120 | 29 | 2 | 37.5 |
| 6410 | 10 | 50 | 130 | 31 | 2.1 | 40 |
| 6411 | 11 | 55 | 140 | 33 | 2.1 | 42.5 |
| 6412 | 12 | 60 | 150 | 35 | 2.1 | 45 |
| 6413 | 13 | 65 | 160 | 37 | 2.1 | 47.5 |
| 6414 | 14 | 70 | 180 | 42 | 3 | 55 |
| 6415 | 15 | 75 | 190 | 45 | 3 | 57.5 |
| 6416 | 16 | 80 | 200 | 48 | 3 | 60 |
| 6417 | 17 | 85 | 210 | 52 | 4 | 62.5 |
| 6418 | 18 | 90 | 225 | 54 | 4 | 67.5 |
| 6419 | 19 | 95 | 240 | 55 | 4 | 72.5 |
| 6420 | 20 | 100 | 250 | 58 | 4 | 75 |
d = bore, D = outside diameter, B = width, r s min = minimum single chamfer dimension. All four are ISO 15 standard values and are the same for every manufacturer. The last column is derived: radial section = (D − d) / 2, the wall thickness you are working with when you size the housing. No load rating and no limiting speed appears here — see the bearings index for why.
Every series at one boresame shaft, different housing
| Series | Type | 10 mm bore | 12 mm bore | 15 mm bore | 17 mm bore | 20 mm bore |
|---|---|---|---|---|---|---|
| 61800 Series | Ultra-thin | 19 × 5 | 21 × 5 | 24 × 5 | 26 × 5 | 32 × 7 |
| 61900 Series | Thin | 22 × 6 | 24 × 6 | 28 × 7 | 30 × 7 | 37 × 9 |
| 6000 Series | Extra-light | 26 × 8 | 28 × 8 | 32 × 9 | 35 × 10 | 42 × 12 |
| 16000 Series | Narrow | 26 × 7 | 28 × 7 | 32 × 8 | 35 × 8 | 42 × 8 |
| 6200 Series | Light | 30 × 9 | 32 × 10 | 35 × 11 | 40 × 12 | 47 × 14 |
| 6300 Series | Medium | 35 × 11 | 37 × 12 | 42 × 13 | 47 × 14 | 52 × 15 |
| 6400 Series | Heavy | — | — | — | 62 × 17 | 72 × 19 |
Outside diameter × width in millimetres, for the five smallest bores in this batch. The full chart across all 21 bores and all 7 series is on the bearings index. Reading a row is what a machine designer does when the shaft is already fixed: the bore does not change, the housing bore does.
Frequently asked questionsreading a bearing designation
Is there such a thing as a 6400 bearing?
Not in the standard plan. The heavy series starts at 6403, a 17 mm bore, so 6400, 6401 and 6402 do not appear in it. That is why the size table on the index page shows a dash against the heavy column for the three smallest bores.
What is the difference between the 6300 and the 6400 series?
Both sit at the top of the diameter ladder, and the heavy series is much the larger. On a 25 mm shaft a 6305 is 62 mm across and 17 mm wide, and a 6405 is 80 × 21. Same shaft, so the housing is the only thing that has to change — and it has to change a lot.
How much more housing does the heavy series need?
A lot, and it is worth pricing before specifying. At a 20 mm bore the light 6204 is 47 mm across, the medium 6304 is 52 mm and the heavy 6404 is 72 mm — 25 mm more housing bore than the light series for an unchanged shaft. Whether the capacity is worth that depends on the load and on what else could carry it; the ratings themselves are catalogue values and are not published here.