RNA 48 Series Needle Roller, No Inner Ring Bearings

Dimension series 48 without the inner ring — the thinner of the two no-inner-ring series here, sharing its outside diameter ladder with the 61800 deep groove series. An RNA4822 is 120 mm across the needle complement, 140 mm outside and 30 mm wide, and the table opens at a 110 mm bore code because ISO 1206's own series 48 table opens there. There is no slash form: the codes run in steps of five the whole way.

Reading the designation. RNA4822 is RNA, then 4, then 8, then 22. The 4 is the width series and the 8 the diameter series, both ISO 15's digits, so the outside diameters are the 61800 ladder's rather than the 61900's; 22 is the bore code, and 22 × 5 = 110 mm is the bore of the complete bearing in this row. This bearing has no bore. It runs on a shaft 120 mm across, which is its Fw, and the code does not name that. The same trap as in the 49 series, one step further up the ladder.

Where the ladder starts is not a choice made here. ISO 1206's own table for dimension series 48 opens at bore code 22, so there is no RNA4800 to RNA4820 to tabulate — the same kind of start as the deep groove 6400 series opening at 6403 and the complete NA 48 series opening at the same row. Nothing in the standard forbids a smaller 48; it is simply not offered, and this library tabulates what the plan publishes. The first row is the one to read twice, because it is where both facts meet: a 110 mm bore code and a 120 mm shaft, in the same designation.

Every code here is a multiple of five, so there is no slash form. The 49 series needs RNA49/22, RNA49/28 and RNA49/32, because three of its bores are not multiples of five and the two-digit code cannot express them at all. This series has no such row: its codes run from 22 to 60, each one multiplying out to a whole multiple of five millimetres, so every designation is the plain four-field form.

Fw, and the same four figures the complete bearing carries. Like every needle roller bearing this type is fixed by a needle complement diameter rather than by a bore: the row is Fw / D / C here and d / Fw / D / B on the complete bearing, which is the same row read with one field fewer. The rollers work in the band between Fw and D — on an RNA4822 that band is 10 mm deep, the same 10 mm the NA4822 has, because it is the same outer ring and the same rollers.

One row of ISO 1206, read twice — and the build checks that it is. As in the 49 series, the 15 rows here are derived from the complete bearings' rows rather than transcribed again, and an assertion compares Fw, D, the width and the chamfer minimum cell by cell at build time. The ISO 1206 page sets out the two readings side by side.

Why no clearance table is printed. ISO 5753-1 does give needle roller bearings a radial clearance table and these sizes fall inside it, so the figure exists — but the catalogue reproductions of it disagree in every clearance group, so none can be confirmed as the standard's own. The table is left out under this library's two-source rule, and the ISO 5753-1 page shows both readings instead.

What is not in this series. Dimension series 59 and 69 are not tabulated here yet, and drawn cup needle roller bearings belong to ISO 3245 rather than ISO 1206. The complete bearings these rows belong to are tabulated beside them, as the NA 48 series — the same table with the inner ring in place. The roadmap on the bearings index records what is still waiting and why.

Every designation in the table below links to its own page with the ISO 1206 boundary dimensions, the bore-code arithmetic, the needle complement diameter and the shaft the bearing runs on.

This series runs from a 120 mm to a 330 mm shaft. The sub-library as a whole reaches 300 mm of bore, and the widest single bearing in it is a 6360, 620 mm across, in the 6300 series. It shares its outside-diameter ladder with the complete bearings of the same dimension series.

Fw = needle complement diameter, D = outside diameter, C = width. All of them are ISO 1206 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 − Fw) / 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. The 2 series whose type has no bore are not rows here: they are indexed by the shaft they run on, and their chart is above.