INANA6913Machined Needle Roller Bearing With Inner Ring, 70 x 100 x 30 mm, Open, X-life — 84 kN Dynamic

Product Description

What this part is

A Schaeffler INA machined needle roller bearing, single row, complete with a separable inner ring: 70 mm bore, 100 mm outside diameter, 30 mm wide. Needle rollers are long, slim cylindrical rollers — length several times diameter. Packing many of them into a small annulus gives an enormous number of line contacts, which is why this bearing carries a very high radial load from a radial section of only 15 mm. Where a deep groove ball bearing of the same bore would need a much larger outside diameter, this one fits inside a tight housing.

The inner ring is the reason to buy this variant:
Needle roller bearings come in two forms and the distinction decides whether the part works on your machine. An NA bearing includes an inner ring. An RNA bearing does not — the needles run directly on the shaft.

Running needles on a bare shaft demands a shaft raceway hardened to bearing hardness, ground, and held to bearing-quality tolerance and surface finish. That is a real manufacturing operation. If your shaft is soft, turned rather than ground, worn, or simply not to that specification, the needles will indent and score it in short order. The NA variant sidesteps the whole problem: the inner ring is a proper hardened, ground raceway that slides onto an ordinary shaft. This is the NA4914-XL, so the inner ring is included.

The inner ring is separable from the cage-and-outer-ring assembly. That is a mounting convenience — press the inner ring on the shaft, the outer assembly into the housing, then bring them together — but it also means the two halves can be handled apart. Keep matched halves together; do not mix an inner ring from one bearing with an outer assembly from another.

Decoding the designation

NA — machined needle roller bearing with inner ring (as against RNA, without).49 — dimension series.14 — bore code, 70 mm.XL — Schaeffler’s X-life performance class: tighter geometry and surface finish, giving a higher rating and longer achievable life than the preceding build.No seal suffix — this is the open version. The sealed variant would carry a 2RSR or similar suffix.

Published ratings and lubrication

Bore (d): 70 mmOutside diameter (D): 100 mmWidth (C): 30 mmDynamic radial load rating Cr: approx. 84,000 N / 18,900 lbfStatic radial load rating C0r: approx. 156,000 N / 35,000 lbfLimiting speed: 6,000 rpm (5,700 rpm quoted for the C3-clearance variant)Internal clearance: normal (the NA4914-XL-C3 is the looser variant)Closure: open, no sealsCage: machined, guided in the outer ringLubrication: groove and oil hole in the outer ringNumber of rows: 1
The outer ring’s lubrication groove and oil hole are worth planning for. Needle bearings run a very large number of small contacts in a thin oil film and they are less tolerant of marginal lubrication than a ball bearing — the slim rollers are prone to skewing if starved. The groove and hole let the housing feed oil or grease directly into the roller path. If your housing has a lubrication port, line it up with the hole; if it does not, this bearing wants a positive lubrication plan rather than a hopeful one.

Quantity, configuration and fitting notes

One bearing in stock, supplied complete: outer ring, needle roller and cage assembly, and the separable inner ring. Being open rather than sealed, it must be lubricated and protected by the housing — there is no built-in grease charge and no barrier to contamination. Needle rollers are unforgiving of misalignment because the long contact line concentrates load at one end of the roller when the rings tilt; bore the housing square and support the inner ring across its full face. Press only on ring faces, never through the rollers or the cage.

Interchange guidance

Search forms include NA4914-XL, NA4914XL, NA 4914 XL, NA-4914-XL, NA 49/14 XL, NA4914, NA49/14. Related builds: NA4914-XL-C3 (C3 clearance), RNA4914 (same envelope without the inner ring — needs a hardened, ground shaft raceway), and NA4914-2RSR if seals are required. Same-envelope equivalents at 70 × 100 × 30 mm are catalogued by IKO (NA4914), NTN, NSK and Koyo under the same ISO NA49-series numbering. Note that the adjacent NA4910-XL is a different bore — do not order by family alone.