TimkenNA48385-3Tapered Roller Bearing Cone – 5.2500 in Bore, 1.6875 in Inner Ring Width, Class 3 Precision, Pressed Steel Cage, Mates With 48320 Cup

Product Description

What this part is

Timken NA48385 *3 inch tapered roller bearing cone. Cone only. Manufacturer: Timken. Manufacturer Part Number: NA48385-3. Base Number: 48385. Series: 48300. Bearing Type: Tapered Roller Bearing Cone. Number of Rows: 1. Rolling Elements: Tapered Rollers. Design Units: Inch. Bore: 5.2500 in (133.35 mm). Inner Ring Width: 1.6875 in (42.8625 mm). Bore Type: Straight. Cage Type: Pressed steel. Cage Material: Steel. Bearing Material: Bearing Steel. Precision Class: Class 3. Unit Quantity: 1 Pc. The matching single cup is the Timken 48320.

Decoding the designation

48385 is the cone number in Timken’s 48300 inch series. The NA prefix marks a cone furnished with a wider inner ring for two-row and TDO service, so the NA48385 is a different part from the plain 48385 and carries a wider inner ring. The trailing 3, written -3, *3 or #3, is Precision Class 3. Class 3 holds a tighter running-accuracy tolerance than standard, which gives lower running vibration and closer shaft location. Searchable forms of the number are NA48385-3, NA48385 *3, NA 48385 #3, NA-48385, NA48385 and 48385.

What these specs mean in practice

Dynamic Radial Load Rating C90, per row: 16,500 lbf (73,300 N). Dynamic Axial Rating Ca90, per row: 9,060 lbf (40,300 N). e Factor: 0.32. K Factor: 1.82. Both ratings are single-row values for this cone. A tapered roller bearing carries combined radial and thrust load through a single row of rollers running on matched cone and cup raceways, and the K factor of 1.82 sets the ratio of radial to thrust capacity for this geometry. The e factor of 0.32 is the load-ratio threshold at which the thrust term enters the equivalent-load calculation. Item Weight: 7.90 lb. Maximum Temperature: 120°C. Minimum Temperature: −40°C. Harmonization Code: 8482.20.00.

Mounting dimensions

Effective Center Location: −0.16 in (−4.1 mm), which places the effective centre inside the cone backface. Maximum Shaft Fillet Radius: 0.140 in (3.5 mm). Shaft Backing Shoulder Diameter, backface (db): 5.83 in (148 mm). Cage Location relative to the backface (Aa): 0.16875 in. Cage Location relative to the frontface (Ab): −0.084375 in. These are the figures that decide whether a given shaft step and fillet will clear the bearing corners.

Quantity and configuration

Unit Quantity: 1 Pc. Cone only: the inner ring with its tapered roller set and pressed steel cage, as one non-separable assembly.

Cone and cup mating

The matching single cup is the Timken 48320, which makes the TS single-row assembly 48385-48320. For two-row service the matching double cups are the Timken 48320D and 48320DC, giving the TDO assemblies 48385-48320D and 48385-48320DC. A D or DC suffix on a cup marks a double cup, which takes two cones on one outer ring — the arrangement the NA prefix on this cone is furnished for.

Interchange guidance

Cross-Reference 1: Bower NA48385. Cross-Reference 2: SKF NA48385. Both are the same cone geometry on the 48385 raceway. The plain 48385 shares the bore and raceway angle but carries a narrower inner ring, so it is a related part rather than a direct substitute where the NA width is being used.