NACHI 7008CYDU Single Row Angular Contact Ball Bearing, 15° Flush Ground, 40 x 68 x 15 mm

The NACHI 7008CYDU is a single row angular contact ball bearing with a 15° contact angle (C), a polyamide cage (Y) and flush-ground faces for universal matching (DU). It measures 40 x 68 x 15mm (bore x outer diameter x width) and carries a basic dynamic load rating of 20,700 N and a basic static load rating of 16,000 N as a single bearing.

A single row angular contact ball bearing has a set contact angle in both rings, so it carries radial, axial or combined load, with any axial load in one direction only. It is generally used in pairs or sets, and the DU flush grinding lets it be combined at random with other bearings of the same type as a back-to-back (DB), face-to-face (DF) or tandem (DT) set. The model reference for this size is 7008CYDU/GLP4: GL is the light preload symbol and P4 is the JIS class 4 tolerance symbol.

Where this product is used

• Machine tool spindles and other precision spindle assemblies
• Gearboxes and speed reducers that carry combined radial and axial load
• Pumps and compressors
• Back-to-back, face-to-face or tandem paired arrangements

Features

• 15° contact angle (C): compared with the 30° design, higher speed and radial load capability with lower axial load capacity, axial load in one direction only
• Polyamide cage (Y), polyamide cages should be used below 120 °C
• Flush ground (DU): any two or more can be mounted back-to-back, face-to-face or in tandem in random combination
• Open design with no seals or shields
• Light preload (GL) and JIS class 4 (P4) in the model reference 7008CYDU/GLP4
• Basic dynamic load rating 20.7 kN, static 16 kN

Key specifications

Fitting and use

Check the load and speed against the figures in the specifications before ordering, and apply a suitable safety factor. Limiting speeds apply to lightly loaded bearings with high quality grease or oil in proper quantity.

The table speeds are for a single bearing, and for contact angle C bearings they apply to JIS class 5 or higher precision.

Polyamide cages should be used below 120 °C.

Flush-ground bearings in a combination should not be mixed with bearings of other types or makes. For a 15° bearing the load factors depend on the ratio of axial load to static rating, so take the equivalent load factors from the range table instead of using a single value.

When fitting, apply force only through the ring that is being pressed on (the inner ring on a shaft, the outer ring in a housing), never through the other ring or the balls.

Choosing the right option

Contact angle. This bearing is the 15° (C) design. Compared with the 30° design it is faster and carries more radial load, with less axial load capacity, and the 15° design is generally applied to high precision bearings of JIS (ISO) class 5 or higher. For heavier axial load at lower speed the 40° (B) range in Related products is the alternative.

Mounting arrangement. Because this bearing is flush ground (DU), it can be combined at random with other DU bearings of the same type. DB (back-to-back) has a long load centre distance and greater moment rigidity, DF (face-to-face) has a short load centre distance and lower moment rigidity, and DT is tandem mounting. DB and DF sets carry axial load in both directions.

Ratings and mass in the tables are for one bearing.

The wider 15° (CYDU) range, 15 to 95mm bore: NACHI 15° single row angular contact ball bearings (28 sizes).

Two more sizes have their own pages: NACHI 7001CYDU (12 x 28 x 8mm), NACHI 7205CYDU (25 x 52 x 15mm).

The 40° (B) single row range, for heavier axial load at lower speed: NACHI 40° single row angular contact ball bearings (26 sizes).