NACHI 0-5 Inch Series O Thrust Ball Bearing 15.875x35.719x15.875 mm

This NACHI range covers 10 single-direction thrust ball bearings with flat back-face housing washers, in inch series O (catalogue designations O-5 to O-18), from 15.875 to 57.15 mm bore (outer diameters 35.719 to 84.931 mm, heights 15.875 to 22.225 mm). Select the size from the drop-down: each size has its own bearing number, load ratings and limiting speeds in the Model Details.

A thrust ball bearing is a shaft washer, a housing washer and a ball and cage assembly running in a groove in each washer. It carries axial load in one direction only and cannot carry any radial load, and it is not suited to high speed running.

Where this product is used

• Vertical shaft pumps, gearboxes and drives
• Screw jacks, lifting screws and clamps
• Turntables, rotary tables and swivel joints
• Machine tool tailstocks and spindle thrust positions
• Low speed, axial load positions in general machinery

Features

• Single-direction thrust ball bearing: carries axial load in one direction only, with a ball and cage assembly running in a groove in each of the shaft washer and the housing washer
• Carries axial load only and cannot carry any radial load, so a separate bearing has to locate the shaft radially
• Flat back-face housing washer for a flat housing shoulder; it does not permit any angular misalignment between shaft and housing
• Not suited to high speed running, because centrifugal force throws the lubricant out; limiting speeds for grease and oil are listed
• Basic dynamic axial load ratings 19.4 to 50.5 kN and static ratings 28.3 to 125 kN across the range

Key specifications

Available sizes

Sizes in the drop-down are bore d x outer diameter D x height T, in mm. The catalogue designation is O-5, O-6 and so on (letter O); this site lists them as 0-5, 0-6 and so on.

Selecting the right option

Pick the bore first, then check the outer diameter D and height T against the space in the housing. Ca is the basic dynamic axial load rating, used for life calculations on a rotating bearing, and Coa is the static rating; check the axial load against both and apply a suitable safety factor.

These are single-direction bearings. Where axial load acts in both directions, a double-direction thrust ball bearing is needed. Where the shaft must be located radially as well, add a separate radial bearing.

Fitting and use

Axial loads only. The bearings cannot carry any radial load. The flat back-face housing washer needs a flat, square seat and does not permit any angular misalignment between shaft and housing.

On a horizontal shaft a minimum axial load must be applied so the balls roll rather than skid. The minimum axial load Fa min (N) is the larger of K x n² and Coa / 1000, where K is the minimum axial factor for the bearing (x 10⁻⁶) and n is the speed in rpm. On a vertical shaft the weight of the shaft often exceeds this, and an opposing external axial load reduces the load that acts on the bearing. The Model Details give K and Coa / 1000 for each size.

Where the Model Details show the shaft washer outside diameter d1 equal to the outer diameter D, the two washers are the same diameter and the housing bore needs a step to clear the shaft washer. Where d1 is smaller than D, no step is needed. Fit the shaft washer (the one with the smaller bore) to the shaft and the housing washer in the housing.

Related products

More from the NACHI thrust ball range: NACHI single-direction thrust ball bearings, 511 / 512 / 513 series, 10 to 120 mm bore (46 sizes), NACHI 0-10 thrust ball bearing, 31.75 x 53.181 x 18.256 mm and NACHI 0-7 thrust ball bearing, 22.225 x 42.069 x 15.875 mm. For heavier axial loads, or where some radial load or shaft misalignment has to be accommodated, see the NACHI spherical roller thrust bearings (60 to 140 mm bore).