INANA4911XLMachined Needle Roller Bearing with Inner Ring — 55 mm ID, 80 mm OD, 25 mm Width, Open, Single Row, X-life

Product Description

What this part is

INA NA4911-XL, a single-row machined needle roller bearing supplied with its own inner ring. Bore: 55 mm. Outside Diameter: 80 mm. Width: 25 mm. Rolling Elements: needle rollers. Closure Type: open. Number Of Rows: 1. Dynamic Load Rating: 65 kN. Static Load Rating: 100 kN. Fatigue Limit Load: 17.3 kN. Limiting Speed: 7,200 rpm. Design: X-life. GTIN: 4012802195545.

Decoding the designation

NA — machined needle roller bearing supplied complete with an inner ring, so it runs on a plain unhardened shaft. The same bearing without the inner ring is an RNA4911.

49 — dimension series 49, the standard-section needle series, which sets the 80 mm outside diameter against the 55 mm bore.

11 — the bore code, 11 x 5 = 55 mm.

XL — X-life execution, INA’s upgraded internal geometry and surface finish rating.

What these specs mean in practice

Dynamic Load Rating: 65 kN. Static Load Rating: 100 kN. On a needle roller bearing the static figure sitting above the dynamic figure is the normal published relationship — the line contact of a full needle complement spreads a stationary load over far more raceway area than a ball bearing does. Fatigue Limit Load: 17.3 kN, the load below which raceway fatigue does not initiate. The whole 65 kN comes out of a 12.5 mm radial wall, which is the reason a needle bearing is chosen: it carries roller-bearing loads in roughly the radial space a ball bearing would need for half of it. Limiting Speed: 7,200 rpm. The inner ring is separable, so shaft and housing can be dressed and measured independently and the bearing does not depend on a hardened and ground shaft journal.

Mounting data

Bore: 55 mm on the supplied inner ring. Outside Diameter: 80 mm. Width: 25 mm across both rings. The outer ring locates in a plain housing bore; the inner ring is a press fit on the shaft and is fitted separately from the outer ring and needle assembly.

Quantity and configuration

Unit Quantity: 1 Pc. One bearing comprises the machined outer ring, the caged needle complement and the separable inner ring. Supplied loose, as it came in mill sleeves of five.

Interchange guidance

Manufacturer part number variants: NA4911-XL, NA4911XL, NA-4911-XL, NA 49/11 XL, NA4911. The designation is an ISO-standard needle bearing envelope, so IKO, SKF, NTN, Koyo and Nachi NA4911 parts share the 55 x 80 x 25 mm boundary dimensions. An RNA4911 is the same outer ring and needle assembly running directly on a hardened shaft, so it is a related part rather than a drop-in for this one.