KoyoImperial Steep-Angle Tapered Roller Bearing Cone, 2.0000 in / 50.8 mm Bore, Mates Cup 72487 – 1 Pc

Product Description

What this part is

This is an imperial single-row tapered roller bearing cone — the inner ring complete with its tapered rollers and cage. It is one half of a tapered roller bearing. The mating cup (outer race) is a separate part number and is not included in this listing.

Decoding the designation

The base number is 72200C, the standard imperial cone designation; its matching cup is 72487, so a complete single-row bearing is a 72200C cone plus a 72487 cup. The dimensional and load data below belong to the 72200C envelope, which is what governs fit.

Published dimensions

Cone bore (d): 2.0000 in / 50.8 mm. Inner ring width (B): 1.2910 in / 32.791 mm. Mating cup 72487 outside diameter (D): 4.8750 in / 123.825 mm. Mating cup 72487 width (C): 1.0000 in / 25.4 mm. Cone weight: 10.32 lb / 4.682 kg.

Published ratings and mounting data

The ratings below are catalogue values for the complete 72200C/72487 single-row assembly, not for the cone on its own.

Dynamic radial rating C1 (1 million rev basis): 48,200 lbf / 214,000 N. Dynamic radial rating C90 (90 million rev basis): 12,500 lbf / 55,500 N. Dynamic axial rating Ca90: 15,800 lbf / 70,100 N. Static radial rating C0: 46,800 lbf / 208,000 N. K factor: 0.79. e: 0.74. Y: 0.81. Geometry factor Cg: 0.0825. Effective load centre: +0.08 in / +2 mm (outside the cone backface). Maximum shaft fillet radius cleared: 0.14 in / 3.600 mm. Shaft backing shoulder diameter, frontface (da): 2.64 in / 67 mm. Shaft backing shoulder diameter, backface (db): 3.03 in / 77 mm. Cup 72487 housing backing shoulder: Da 4.6 in, Db 4.02 in.

What these specs mean in practice

This is a steep-angle tapered roller bearing and the numbers say so plainly: the K factor is 0.79 and the axial rating Ca90 of 15,800 lbf is higher than the radial C90 of 12,500 lbf. That is the opposite of an ordinary taper such as a 3767, where K is around 1.7 and thrust capacity is well below radial. A steep contact angle buys thrust capacity and axial stiffness at the cost of radial capacity per unit of envelope, which is why this geometry is chosen for vertical shafts, thrust-dominant pinion positions and machine tool tables. The positive effective load centre, +0.08 in outside the cone backface, is another consequence of the steep angle — the reaction point sits outboard of the ring rather than inside it, so bearing-spacing and moment calculations must use the effective centre or the span will be underestimated.

Quantity and configuration

This listing ships 1 Pc — one 72200C cone. No cup, no spacer, no seal.

Fitting notes

Press the cone on square with a driver bearing on the backface only; never load the rollers or cage. Keep the shaft shoulder inside the da/db range so the ring is supported. Steep-angle tapers are less forgiving of a sloppy setting than shallow ones: a preload that would be harmless on a 1.7 K bearing will run hot here, because the axial deflection per unit of preload is much smaller. Set the end play or preload only after the cup is fully home in its housing.

Interchange guidance

72200C is a standardised imperial cone, so 72200C cones from Koyo, Timken, NTN, Bower/BCA and Federal-Mogul interchange with one another and with any of those makers’ 72487 cups. Cup 72500 is also listed against this cone as an alternative outer race. Note that the plain 72200 and 72200C are not freely interchangeable — the C denotes the steep-angle roller and raceway geometry that produces the ratings above, and substituting a different angle changes both the thrust capacity and the induced-thrust behaviour of the whole shaft.