Timken780WTapered Roller Bearing Cone – 4.0000 in Bore, 1.8900 in Cone Width, K Factor 1.51, Case-Hardened Steel, Stamped Steel Cage, Matching Cup 772.

Product Description

What this part is

Timken 780W tapered roller bearing cone — the inner ring, rollers and cage assembly of a single-row TS bearing. Bore is 4.0000 in (101.600 mm) and inner ring width 1.8900 in (48.006 mm). Case-hardened steel rings and rollers in a stamped steel cage. Cone only. The matching cup is the Timken 772, with the 772A as the alternative execution.

Decoding the designation

780 is the Timken cone part number in the imperial single-row series. The trailing W is a Timken execution letter carried here as a searchable variant; the Class 2 precision execution of this cone is designated 780-2 instead.

What these specs mean in practice

The K factor of 1.51 is the ratio of radial to thrust capacity and sets how much axial load the raceway angle will carry for a given radial load. Timken publishes a one-million-revolution dynamic radial rating C1 of 77 800 lbf (346 000 N), a ninety-million-revolution radial rating C90 of 20 200 lbf (89 700 N), a ninety-million-revolution thrust rating Ca90 of 13 300 lbf (59 200 N) and a static radial rating C0 of 111 000 lbf (495 000 N). Lubrication life factors are G1 227.3, G2 41.3 and geometry constant Cg 0.107. The assembly weighs 23.66 lb (10.731 kg).

Quantity and configuration

One piece, cone only. Tapered roller bearings of this type are typically mounted in opposing pairs on a shaft.

Fitting notes

Shaft backing shoulder diameter is 4.45 in at the frontface and 4.69 in at the backface, and the maximum shaft fillet radius cleared by the bearing corner is 0.14 in. Effective centre location is −0.32 in, the negative figure placing the effective centre inside the cone backface. Cage location is 0.13 in from the backface and 0.07 in from the frontface.

Interchange guidance

The 780-2 is the Class 2 precision execution of the same cone and a related part rather than a straight interchange. Timken lists the 772 and 772A as the cups that run against this cone.