SKF1317Double-row self-aligning ball bearing – straight bore, 85 mm ID, 180 mm OD, 41 mm width, open, pressed steel cage, CN internal clearance

Product Description

What this part is

The FAG 1317 is a double-row self-aligning ball bearing, 85 mm bore by 180 mm outside diameter by 41 mm width, with a straight cylindrical bore and open faces. Two rows of balls run in a single concave spherical raceway machined into the outer ring, so the inner ring, ball complement and cage swivel freely inside the outer ring as an assembly.

Decoding the designation

The 13 prefix identifies the self-aligning ball family in the wider 130 dimension series, and the trailing 17 is the bore code, which multiplied by five gives the 85 mm bore. No K suffix means the bore is straight and seats directly on the shaft. No clearance suffix means normal CN radial internal clearance. Norma is a FAG trade name that appears on cartons and rings of this era and refers to the same bearing.

What these specs mean in practice

The spherical outer raceway makes this design almost indifferent to angular error between the two bearing seats, which is why it is the traditional choice for long line shafts, textile machinery and agricultural drives where the housings are bolted to a fabricated frame rather than a machined bore. The trade-off is contact geometry: the balls sit in a wide-radius spherical outer race, so static capacity is modest relative to the dynamic rating and thrust capability is secondary to radial. Friction is the lowest of any rolling bearing type, which keeps running temperature down at continuous speed.

Bore form

Straight bore, located axially by a shaft shoulder, spacer or end cover. The tapered-bore member of the same family is the 1317K, which mounts on an H217 adapter sleeve and has a different seat diameter.

Quantity and configuration

One piece, open both sides, supplied as a complete bearing with both rings, both ball rows and the cage.

Fitting notes

The inner ring takes the interference fit on the shaft and mounting force is applied to that ring. Because the outer ring is a plain cylindrical seat with a spherical raceway inside it, housing bore alignment between the two ends of a shaft is taken up by the bearing itself once the housings are drawn down.

Interchange guidance

Same-size, same-design equivalents are the SKF 1317, NSK 1317 and NTN 1317. FAG 1317-M is the same envelope with a machined brass cage and 1317-M-C3 adds greater than normal clearance; both are related sizes rather than exact matches, since cage and clearance change the speed rating and the mounted fit. The 1317J is a double-row angular contact bearing on the same envelope and is a different bearing type entirely.