NA 48 Series Needle Roller Bearings

Needle roller, width series 4 on diameter series 8 — the same outside-diameter ladder the 61800 deep groove series stands on, not the 61900's. A NA4822 is 110 × 120 × 140 × 30 where its partner in the 49 series, NA4922, is 110 × 125 × 150 × 40. Where the ladder starts is not our choice: ISO 1206's own table for dimension series 48 begins at a 110 mm bore, so nothing below that exists to tabulate. The bore codes run in steps of 5 the whole way, so this series has no slash form.

Reading the designation. NA4822 is NA, then 4, then 8, then 22. The 4 is the width series and the 8 the diameter series, both ISO 15's digits, and 22 is the bore code read the usual way: 22 × 5 = 110 mm. Diameter series 8 is the ladder the 61800 deep groove series stands on, so a NA48 shares its outside diameter with a 61800 of the same bore rather than with a 61900. In this library the two never meet, because the 61800 series stops at a 100 mm bore and this one starts at 110 — the identity is a fact about the two ladders, not a row you can look up on this site. Against the 49 series, which does overlap, the 48 is the smaller-across of the two at every shared bore.

Where the ladder starts is not a choice made here. ISO 1206's own table for dimension series 48 opens at a 110 mm bore, so there is no NA4800 to NA4820 to tabulate — the same kind of start as the deep groove 6400 series opening at 6403 and the spherical roller 223 series opening at 22308. Nothing in the standard forbids a smaller 48; it is simply not offered, and this library tabulates what the plan publishes.

Every bore code here is a multiple of five, so there is no slash form. The 49 series needs NA49/22, NA49/28 and NA49/32 because three of its bores cannot be written by the two-digit code. This series has no such bore: its codes run from 22 to 60, and each one multiplies out to a whole multiple of five millimetres, so every designation is the plain four-field form.

Fw, and the same four dimensions. Like every needle roller bearing, this type is fixed by four dimensions rather than three: d, Fw, D and B, where Fw is the needle complement diameter — the inscribed circle the rollers run on. The rollers work in the band between Fw and D, not between d and D, which is why the front view on each page draws a third circle. On a NA4822 that band is 10 mm deep.

One chamfer value, from ISO 582. As in the 49 series, ISO 1206 lays out a single r s min for the corner and the numeric limits come from ISO 582. There is no per-ring pair here, so the column is complete rather than half-filled.

Why no clearance table is printed. ISO 5753-1 does give needle roller bearings a radial clearance table, and these bores 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. Under this library's rule that a published figure needs two independent sources agreeing, the table is left out and the ISO 5753-1 page shows both readings instead.

Why 59 and 69 are not the neighbouring pages. The other three needle dimension series tabulated here — the NA 49 series, the NA 59 series and the NA 69 series — all stand on diameter series 9, and this one stands on diameter series 8. Those three are one envelope in three widths; this is a different envelope, with the 61800 outside diameters where they have the 61900's. So the four series divide two ladders between them, and no row on this page has a same-bore partner on those three. What is not in this series is the drawn cup needle roller bearing, which belongs to ISO 3245 rather than ISO 1206 and is a different plan altogether; the roadmap below records it. What is beside it. The same dimension series is also tabulated without its inner ring, as the RNA 48 series — the same boundary table with the inner ring left out, so an RNA4822 is 120 × 140 × 30 mm where this NA4822 is 110 × 120 × 140 × 30, and the two run on different shafts even though the code reads the same. The ladder starts in the same place for the same reason: the series 48 table opens at a 110 mm bore, so the RNA 48 opens at the 120 mm shaft that bore's complement measures.

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 same-bore comparison against every other series and type.

This series runs from a 110 mm to a 300 mm bore. 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. This is one of the series that gets to that top bore.

d = bore diameter, Fw = needle complement diameter, D = outside diameter, B = 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 − 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. The 6 series whose type has no bore are not rows here: they are indexed by the shaft they run on, and their chart is above.