FAGK43096/43319DDouble-Row TDO Tapered Roller Bearing Assembly, 0.960 in Bore x 3.1875 in OD x 2.1875 in Wide, Two Cones in One Double Cup

Product Description

What this part is

This is a two-row tapered roller bearing in the TDO configuration — Tapered Double Outer. Two 43096 cone assemblies run in a single wide 43319D double cup. Bore is 0.9600 in (24.384 mm), cup outside diameter 3.1875 in (80.963 mm), overall width across the cone backfaces 2.1875 in (55.563 mm). Stamped steel cages, inch design units, 43000 series.

Correcting the source data

The previous listing gave bore and outside diameter but no width at all, which is the one dimension a buyer of a two-row bearing most needs — because the width of a TDO is not the width of a single-row bearing of the same bore. The published assembly width is 2.1875 in / 55.563 mm across the two cone backfaces, and it has been added. The bore of 0.960 in and the outside diameter of 3-3/16 in were both correct and are unchanged.

Decoding the designation

K — FAG’s prefix marking an inch-series tapered roller designation. It signals the numbering system, not a design difference.43096 — cone number, 43000 inch series; sets the 0.9600 in bore.43319D — cup number, where the trailing D means double cup: one wide outer ring carrying two opposed raceways. That letter is the whole reason this is a two-row bearing.TDO — the resulting arrangement, two rows back-to-back inside the double cup.

Why the two-row rating, not the single-row one

This trips people up regularly. A TDO’s capacity is a two-row figure, and quoting the single-row C90 for it understates the bearing by roughly a factor of four. Published values:

Bore (d): 0.9600 in / 24.384 mmCup outside diameter (D): 3.1875 in / 80.963 mmAssembly width across cones (T): 2.1875 in / 55.563 mmCone width (B), each: 0.9478 in / 24.074 mmDouble cup width (C): 1.5625 in / 39.688 mmDynamic radial rating, two row, 1 million rev (C1): 36,000 lbf / 160,000 NDynamic radial rating, two row, 90 million rev (C90(2)): 9,340 lbf / 41,500 NDynamic radial rating, one row, 90 million rev (C90): 5,360 lbf / 23,900 NDynamic thrust rating, 90 million rev (Ca90): 6,130 lbf / 27,300 Ne factor 0.67, K factor 0.87, Y1 1.01, Y2 1.5Cone backface backing diameter (db): 1.59 in / 40.5 mmCup frontface backing diameter (Da): 2.94 in / 73.91 mmEffective centre location: −0.08 in / −2 mm (inside the cone backface)Cone backface radius to clear (R): 0.03 in / 0.800 mm; cup backface radius to clear (r): 0.06 in / 1.5 mmCage location relative to cone backface (Aa): 0.10 in / 2.5 mmDouble cup weight alone: 2.94 lb / 1.335 kgGeometry factor Cg 0.0774; G1 16.8, G2 7.57

Static rating C0 is not published for this reference. That is not an omission on our part: Timken rates inch tapered roller bearings on the C90 / Ca90 ninety-million-revolution system rather than on the ISO C0 static figure, so no C0 exists to quote. Assembly weight and the FAG-specific ratings are likewise not published.

What the K factor of 0.87 tells you

K is the ratio that follows from the cup angle, and 0.87 is low — well under the 1.5 to 1.8 typical of general-purpose tapered roller bearings. A low K means a steep cup angle, and a steep cup angle means the bearing is built to take thrust. Combined with the e factor of 0.67, which is high, this is a bearing whose design intent is heavy axial load with a comparatively modest radial component. Put in a TDO arrangement, where thrust is taken in both directions, that makes it a locating bearing: something that holds a short shaft axially against reversing loads rather than simply supporting its weight.

Note the negative effective centre location of −0.08 in. The load line crosses the bearing axis inside the cone backface, which for a back-to-back pair means the two load lines cross close together. Practical consequence: the effective bearing spread is narrow, so this arrangement is good at holding position and reversing thrust but is not the tool for reacting a large overturning moment. If moment stiffness is what you need, a wider-spread TDO is the right answer.

A note on the brand

43096 and 43319D are industry-standard inch designations, not FAG-proprietary numbers, so the dimensions and calculation factors above are fixed by the standard and a FAG part interchanges dimensionally with any reputable maker’s. Being straight about provenance: the data above is the published inch-series data for 43096/43319D, not a FAG-hosted table — FAG does not publish this reference online. Dimensions and factors are safe to rely on; if you need FAG-specific certified ratings or documentation, that has to come from Schaeffler.

Quantity and configuration

One hundred and forty-seven complete assemblies on hand. Each unit is one bearing: two 43096 cones plus one 43319D double cup. At that depth this is an OEM-scale position rather than an MRO spare — enough for a production run, and worth asking about on volume.

Fitting notes

TDO endplay is ground in at the factory as a controlled cone backface stack height. Clamp the two cones solidly together against the shaft shoulder; do not shim, and never mix cones between assemblies, because that destroys the ground setting. Respect the small clearance radii — 0.03 in at the cone backface, 0.06 in at the cup backface — and press the cup in square, bearing on the cup face and never on a raceway.

Interchange guidance

Cross-references: K43096/43319D, 43096/43319D, 43096-43319D, 43096 43319D, 43319D, 43319-D, K43096-43319D. Components: cone 43096, double cup 43319D. Related: 43096/43319 (single row), 43319 (single cup). Because these are standard inch numbers, Timken, NSK, Koyo and others catalogue the same designation.