NACHI7205CYDB/GLP5Super-Precision Angular Contact Ball Bearing 25x52x15 mm 15° ABEC 5 Light Preload DB Matched Pair

Product Description

What this part is

A Nachi 7205CYDB/GLP5 super-precision angular contact ball bearing set — two single-row bearings, 25 mm bore by 52 mm outside diameter by 15 mm wide each, ground and supplied as a back-to-back matched pair at light preload. Open on both faces, no shields and no seals.

Decoding the designation

In Nachi’s scheme 7205 is the single-row angular contact size, CY is the 15° contact angle super-precision execution, DB is a back-to-back arrangement, GL is light preload and P5 is the ISO 5 tolerance class, equivalent to ABEC 5. The pair is ground as a fixed DB set: the offset is machined into these two specific rings, so the two pieces belong together.

Published specifications

Bore: 25 mm (0.9843 in)
Outside diameter: 52 mm (2.0472 in)
Width per bearing: 15 mm (0.5906 in)
Total width of the pair: 30 mm (1.1811 in)
Contact angle: 15°
Precision class: P5, equivalent to ABEC 5
Preload: light (GL)
Arrangement: DB, back-to-back matched pair
Closure: open both faces
Rows: 1 per bearing
Rolling elements: steel balls

What these specs mean in practice

A 15° contact angle carries less thrust than a 25° or 40° bearing of the same size and runs faster and cooler, which places it in high-speed spindle and precision drive positions. A back-to-back arrangement puts the two contact-angle lines diverging outward, giving a wide effective load span and high resistance to moment loading, so a DB pair holds a shaft rigid against tilting in a way a face-to-face pair does not. Light preload keeps the ball complement in defined contact for stiffness and runout control at the lowest heat generation of the preload grades, and P5 tolerances hold bore, outside diameter and ring runout to super-precision limits.

Quantity and configuration

2 Pcs, supplied as one back-to-back matched pair at light preload. The DB offset is fixed at grinding, so the set is used as the pair it was ground as.

Fitting notes

The pair mounts with the wide faces outward for the back-to-back geometry, clamped through the ring faces so the ground offset sets the preload; shaft and housing seats are held to the fits appropriate to a P5 bearing.

Interchange guidance

7205-CY-DB-GL-P5 and 7205CYDB/GLP5 are the same designation written two ways. A 7205 at 25° or 40° contact angle, in a face-to-face (DF) or tandem (DT) arrangement, at medium or heavy preload, or in a universally ground single execution, is a related size rather than an equivalent. The Fafnir/Timken 2MM205 is a 15° part on the same envelope at P4S tolerances, a different precision class and so also a related size.