NA 49 SeriesNeedle RollerLightBore code 17ISO 1206

NA4917 Single-row Needle Roller Bearing With Machined Rings

NA4917 is a single-row needle roller bearing with machined rings, light series, with a 85 mm bore, a 100 mm needle complement diameter, a 120 mm outside diameter and a 35 mm width. Those numbers — the bore, needle complement diameter, outside diameter, width and the 1.1 mm minimum chamfer — are ISO 1206 standard values, identical for every manufacturer.

NA4917 — bore 85 mm, outside diameter 120 mm, width 35 mm (B)Ø d 85Ø D 120Ø Fw 100front viewB 35r s min 1.1side view
NA4917 — single-row needle roller bearing with machined rings, light seriesISO 1206 boundary dimensions · mm · Not to scale
bore d85 mm
needle complement diameter Fw100 mm
outside diameter D120 mm
width B35 mm
Bore code17
Radial section17.5 mm
Designation
NA4917
Type
Single-row needle roller bearing with machined rings — radial
Bore code
17 — 85 mm
Bore d
85 mm (3.3465 in)
needle complement diameter Fw
100 mm
outside diameter D
120 mm
width B
35 mm — the assembled width
Chamfer, r s min
1.1 mm — minimum, not nominal
Radial section
17.5 mm = (D − d) / 2

Nominal values in millimetres as published in ISO 1206, the boundary dimension plan this type is tabulated in. The chamfer figure is the minimum single chamfer dimension the plan gives (r s min); the matching maximum is in ISO 582 — which is why the row says “min” and not an equality. A bearing that has been fitted with shields or seals carries the same dimensions, because none of the suffixes touches the boundary dimension plan.

Reading the designationwhere 85 mm comes from

Type codeNA — single-row needle roller bearing with machined rings
Dimension series49 — light
Bore code17
Bore arithmetic17 × 5 = 85 mm

The designation is three fields: type, the series and the bore code. For codes 04 and above the bore is the code multiplied by five, which is why 17 gives 85 mm. The four exceptions are 00, 01, 02 and 03 at 10, 12, 15 and 17 mm.

Position in the series21 of 28 in NA 49 Series

No radial clearance table on this pagesingle-row needle roller bearing with machined rings

ISO 5753-1 does give needle roller bearings a radial clearance table of their own, and the bore of a na49-series bearing falls inside it. What stops a table appearing here is not the standard but the reproductions of it: the catalogue versions consulted contradict each other in every clearance group, so none of them can be confirmed as the standard’s own, and this library does not publish a figure it cannot attribute. That is the opposite of the tapered and thrust cases above — there the standard fixes a different quantity, here the quantity is fixed and the figures differ.

What is deliberately not publishedwhy there is no load rating here

No load rating, no limiting speed and no mass appears on this page. Those are catalogue values rather than standard values: ISO 281 defines how a dynamic rating is calculated, not what it comes out as, and the result depends on internal geometry — ball or roller diameter, the complement, raceway conformity — that none of the boundary dimension plans (ISO 15, ISO 355, ISO 104, ISO 1206) fixes. Published catalogue figures for one and the same designation differ between makes by several percent at these sizes, and limiting speed additionally depends on lubrication and on whether the bearing is open, shielded or sealed. Publishing any single figure here would dress a catalogue entry up as a property of the designation. Take the rating from the catalogue of the bearing you actually buy.

The dimensions above are a different matter, and they are the reason a designation is worth anything: the boundary dimensions — bore, outside diameter and the section dimensions of the plan this type is tabulated in, plus the chamfer minimum where that plan gives one — are fixed by the standard, so every maker's bearing of this designation fits the same shaft and the same housing.

Same bore, every series and typewhat a 85 mm shaft would take instead

DesignationSeriesTypeDOverall size (B / T / H)Section (D − d)/2vs NA4917
NA4917Light — this bearingNeedle roller12035 B17.5—
6171761700 Series — Extra-thinDeep groove ball10510 B10-15 mm on D
6181761800 Series — Ultra-thinDeep groove ball11013 B12.5-10 mm on D
5111751100 Series — LightThrust ball11019 H12.5-10 mm on D
6191761900 Series — ThinDeep groove ball12018 B17.50 mm on D
5121751200 Series — MediumThrust ball12531 H20+5 mm on D
60176000 Series — Extra-lightDeep groove ball13022 B22.5+10 mm on D
1601716000 Series — NarrowDeep groove ball13014 B22.5+10 mm on D
62176200 Series — LightDeep groove ball15028 B32.5+30 mm on D
12171200 Series — LightSelf-aligning ball15028 B32.5+30 mm on D
22172200 Series — Light, wideSelf-aligning ball15036 B32.5+30 mm on D
3021730200 Series — LightTapered roller15030.5 T32.5+30 mm on D
NU217NU 2 Series — LightCylindrical roller15028 B32.5+30 mm on D
NU2217NU 22 Series — Wide lightCylindrical roller15036 B32.5+30 mm on D
22217222 Series — Wide lightSpherical roller15036 B32.5+30 mm on D
63176300 Series — MediumDeep groove ball18041 B47.5+60 mm on D
13171300 Series — MediumSelf-aligning ball18041 B47.5+60 mm on D
23172300 Series — Medium, wideSelf-aligning ball18060 B47.5+60 mm on D
3031730300 Series — MediumTapered roller18044.5 T47.5+60 mm on D
21317213 Series — MediumSpherical roller18041 B47.5+60 mm on D
22317223 Series — Wide mediumSpherical roller18060 B47.5+60 mm on D
64176400 Series — HeavyDeep groove ball21052 B62.5+90 mm on D

22 series across seven bearing types, one bore: the shaft diameter is the same in every row, so the only thing that changes is what the housing and the axial space have to accommodate. Outside diameter and the overall size are standard boundary dimensions in the plan each type is tabulated in (ISO 15 / ISO 15 / ISO 355 / ISO 104 / ISO 15 / ISO 15 / ISO 1206) — the same figure for every manufacturer. The section column is derived as (D − d) / 2. Load capacity rises with the outside diameter, but the figure itself has to come from the manufacturer’s catalogue for the bearing you actually buy — see above.

Where this part sitsthe family drawing, for context

Schematic front view of a deep-groove ball bearing with bore and outside diameter dimensionedØ D 52Ø d 25
6205d 25 · D 52 · B 15 mm
BearingsOne of the 13 mechanical part families in this database. This page covers seven bearing types — deep groove ball, self-aligning ball, tapered roller, thrust ball, cylindrical roller, spherical roller and needle roller — each tabulated in its own boundary dimension plan.All families →