223 Series Spherical Roller Bearings

The widest envelope of the three, on the 213's outside diameters: a 22308 is 40 × 90 × 33 mm against 40 × 90 × 23 for the 21308, and the series ends at 22320, 100 × 215 × 73. Those same diameters are the self-aligning 2300's — a 2308 is 40 × 90 × 33 — so what the extra width buys is roller length inside an unchanged housing envelope, which is the load a mill stand or a screen is after when it steps up from the 222. Note where the ladder starts: the smallest bore the tables checked carry is 40 mm, not 25 as in the other two series — the catalogue range opens there, so the table below opens there too, and the missing rows are not an omission on this page.

Reading the designation. A 22308 is the type code 2 for a double-row spherical roller bearing, the dimension series 23 and the bore code 08. The 23 carries both of its digits: 2 for the width series and 3 for the diameter series. The diameter series is the one that fixes the outside diameter and it is 3, the same rung the 213 and the deep groove 6300 stand on — which is why the 22308 and the 21308 are both 90 mm across. The width series is what moves: 2 here against the 213's 1. The bore code is the familiar one, read the same way: 00, 01, 02 and 03 are 10, 12, 15 and 17 mm, and from 04 upwards the code multiplies by five.

The ladder starts at a 40 mm bore, and that is a fact about the catalogues. The first row here is 22308 and there is no 22300 to 22307: the 223 designation opens at bore code 08 in the tables checked, which is the same kind of start as the deep groove 6400 series opening at 6403. That is where the published range opens, not a claim that the smaller sizes do not exist — and it is why the table below has 13 rows while the 213 and the 222 have 16 each.

Why the extra width, and what it buys. The 223 is the 213's envelope widened: same bore, same outside diameter, a ring 10 mm wider at the bottom of the series and 26 mm wider at the top. A wider ring means a longer roller path, so the bearing carries more radial load without any increase in outside diameter — the housing does not change at all, and that is the cheapest capacity there is. The self-aligning 2300 family stands on these same envelopes, so a 2308 and a 22308 are both 40 × 90 × 33 mm, and the cylindrical NU 23 shares them up to a 75 mm bore.

What the type buys, and what it costs. Two rows of barrel rollers on a sphered outer raceway — misalignment tolerance and a heavy radial rating in one bearing. It is the type a mill stand, a screen or a heavy gearbox reaches for when the shaft is thick and the housing cannot grow. The cost is axial room, and it is visible in the table: a 22308 stands 33 mm wide where the deep groove 6308 that shares its 40 × 90 envelope is 23. How much misalignment a specific bearing absorbs and how much axial load it will take are catalogue values for the individual part, not properties the boundary dimension plan fixes, so neither figure appears 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 40 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.