213 Series Spherical Roller Bearings

The narrow one of the three spherical roller series here: a 21305 is 25 × 62 × 17 mm and the series runs to 21320 at 100 × 215 × 47. Its outside diameters sit on the 6300 ladder — a 21308 is 40 × 90 × 23 mm, the same three figures a deep groove 6308 and a self-aligning 1308 carry — so it drops into a housing already bored for that envelope while carrying two rows of barrel rollers instead of balls. The 1 in the dimension series is the width series: the 223 takes these same outside diameters and widens the ring, and choosing this one is choosing not to.

Reading the designation. A 21305 is three fields: 2 is the type code for a double-row spherical roller bearing, 13 is the dimension series and 05 is the bore code. The leading 2 is written out here, unlike the type code of the self-aligning 2204 — and this is the one place in the library where a leading 2 means two different things, so read the digit count rather than the prefix: a 2204 is four digits, a 21305 is five. The bore code is the one used throughout: 00, 01, 02 and 03 are 10, 12, 15 and 17 mm, and from 04 upwards the code multiplies by five, which is why 05 gives 25 mm.

Why the envelope looks familiar. The middle field carries two digits: 1 is the width series and 3 is the diameter series. The diameter series is the one that sets the outside diameter, and 3 is the rung the deep groove 6300 and the self-aligning 1300 already stand on — so the three tables run together over the bores they share. A 21305 is 25 × 62 × 17 mm, and so is a 6305 and a 1305; at the top of the series a 21320 is 100 × 215 × 47 mm, which is the 6320's and the 1320's three figures to the millimetre. The range tabulated here is 25 to 100 mm, so the 6300 and the 1300 both reach further down the ladder than this series does.

What the type buys, and what it costs. Two rows of barrel rollers running on a sphered outer raceway. The sphered raceway is the whole point of the type: the outer ring can tilt relative to the inner without disturbing the rollers, so the bearing keeps working through the shaft deflection and housing distortion that would shorten the life of a deep groove bearing. What it does not buy is room. The 213 sits on the 6300's envelopes, so a 21305 and a 6305 are both 25 × 62 × 17 mm: the swap costs no height and no axial space, and everything that changes is inside the envelope. How much misalignment a given bearing absorbs and how much axial load it will carry are catalogue values for the specific part, not properties the boundary dimension plan fixes, so neither figure is published here.

Why there is a chamfer column on these pages, and none on the cylindrical roller pages. ISO 15 gives a spherical roller bearing a single r s min for the corner, so one value covers the plan. For a cylindrical roller bearing the same standard gives a separate minimum for each ring, and of the sources checked here only one prints both — not enough under this library's rule that a published figure needs two independent sources, so that type's column is left out rather than half-filled. The ISO 582 page explains what the two values are and why they differ.

Every designation in the table below links to its own page with the ISO 15 dimensions, the bore-code arithmetic, the radial internal clearance ranges ISO 5753-1 gives for this type, and the same-bore comparison against every other series and type.

This series runs from a 25 mm to a 100 mm bore. The sub-library as a whole reaches 300 mm, and the widest single bearing in it is a 6360, 620 mm across, in the 6300 series. This one stops short of it.

d = bore diameter, D = outside diameter, B = width. All of them are ISO 15 standard values and are the same for every manufacturer. r s min is the minimum single chamfer dimension the plan gives; its matching maximum is in ISO 582, which is why the column says “min” and not an equality. 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.

Outside diameter × overall size in millimetres, for the 5 smallest bores in this database. The full charts, one per type, are 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. Across the type boundary the last number changes meaning — it is a width above and a height below — so compare within a type, then decide whether the job wants a ball bearing, a tapered roller or a thrust bearing at all.