Timken74556Tapered Roller Bearing Cone – 5.5108 in Bore, 1.8750 in Width, K Factor 1.20

Product Description

What this part is

Timken 74556 tapered roller bearing cone. This is the inner ring with its tapered roller set and cage, the rotating half of a Timken TS single-row inch tapered roller bearing. Bore Diameter: 5.5108 in (139.974 mm). Overall Width: 1.8750 in (47.625 mm) inner ring width. Item Weight: 12.85 kg (28.34 lb). Dynamic Load Rating: 354,000 N (79,500 lbf) at C1. Static Load Rating: 614,000 N (138,000 lbf). Rolling Elements: Tapered Roller. Number Of Rows: 1. Bore Type: Straight. Cage Type: Pressed. Bearing Material: case-carburized alloy steel. Design Units: Imperial. Series: 74500. Base Number: 74556.

Decoding the designation

74556 — a cone number in Timken’s inch 74500 tapered roller series, fixing the 5.5108 in bore and the 1.8750 in inner ring width.

What these specs mean in practice

K Factor: 1.20. A K factor of 1.20 is a steep taper by inch-series standards: the raceway angle is close enough to 45 degrees that the bearing carries a large thrust component alongside its radial load, which is why a 74500-series position is chosen for heavy combined loading rather than pure radial duty.

Dynamic Load Rating: 354,000 N (C1, at 1 million revolutions, ISO method). Dynamic Radial Load Rating at 90 million revolutions (C90): 91,700 N. Dynamic Axial Rating at 90 million revolutions (Ca90): 76,500 N — the thrust figure sits at 83 per cent of the radial figure, which is the numerical expression of that steep taper. Static Load Rating: 614,000 N.

G1 Factor: 362.9. G2 Factor: 68.5. Geometry Factor (Cg): 0.134, the geometry constant for the lubrication life adjustment factor a3l.

Mounting data

Maximum Shaft Fillet Radius: 0.140 in (3.600 mm) — the largest fillet the shaft shoulder may carry and still be cleared by the cone corner. Shaft Backing Shoulder Diameter, frontface (da): 5.98 in (152 mm). Shaft Backing Shoulder Diameter, backface (db): 6.22 in (158 mm). Effective Centre Location: 0.09 in (2.3 mm), measured outside the cone backface. Cage Location relative to backface (Aa): 0.18 in. Cage Location relative to frontface (Ab): 0.10 in.

Quantity and configuration

Unit Quantity: 1 Pc. Cone only — inner ring, rollers and cage. The matching cup is the Timken 74845.

Interchange guidance

74556 is an inch tapered roller cone number on the common industry dimensional standard, so a 74556 from another inch-series maker carries the same bore, width and raceway angle and is a direct substitution. Cross-references: Koyo 74556, NTN 4T-74556, NSK 74556, Bower / BCA 74556, Fersa 74556.