NSKMatched Back-to-Back (DB) Tapered Roller Bearing Pair with Ground Spacer, 50 mm Bore x 80 mm Outside Diameter, P5 / ABEC 5 Precision, Two Cones + Two Cups + One Spacer per Set

Product Description

What this part is

NSK HR33010JDBP5+KL7CP45 is a factory-matched pair of metric single-row tapered roller bearings, supplied as a back-to-back DB set with a ground spacer ring. Bore Diameter: 50 mm. Outside Diameter: 80 mm. The rings and the spacer are ground together as a unit to produce a specified preload when they are clamped up.

Composition: five pieces per set — two cones (inner rings with roller and cage assemblies), two cups (outer rings) and one ground spacer ring. Ring markings read NSK HR 33010J with the DBP5 pairing mark; the carton is labelled HR33010JDBP5+KL7CP45, lot 406, and the original NSK inspection slip is present.

Decoding the designation

HR — NSK’s high-capacity tapered roller design. Larger and longer rollers in the same envelope than the base metric series, so the load rating rises without a dimensional change.

33010 — ISO metric tapered roller size designation: 50 mm bore, 80 mm outside diameter.

J — pressed steel cage.

DB — back-to-back arrangement. The two cup backfaces sit together, so the effective load lines diverge outward.

P5 — ISO precision class 5, equivalent to ABEC 5. Two grades tighter than standard P0/ABEC 1 on bore, outside diameter, and on radial and axial runout.

+KL7CP45 — the matched spacer element supplied with the pair. The plus sign in NSK nomenclature denotes an accompanying component ground to suit.

What these specs mean in practice

Arrangement: DB, back-to-back. The two rows’ load lines spread apart as they travel outward, which gives the pair a wide effective support span even though the two bearings are physically adjacent. That translates into moment stiffness — resistance to a shaft tilting — from a single short bearing position. Face-to-face (DF) pairs converge their load lines to a narrow span, the arrangement used where an assembly must tolerate misalignment.

Precision Class: P5 (ISO class 5 / ABEC 5). A tighter class means the raceways are more concentric with the bore, so a shaft mounted in these bearings turns with less radial and axial wander at the working end. P5 tapered pairs are specified for machine tool spindles, rotary tables, worm gear reducers and precision indexing heads.

Preload: set by the ground spacer. Tapered roller bearings have no built-in clearance, so the working preload is set by how far the two rows are pushed together on assembly. A matched set with a ground spacer achieves the specified preload when the stack is clamped solid.

Quantity and configuration

Priced and sold per matched set. Each set is five pieces: two cones, two cups, one ground spacer.

Published dimensional data

Bore d: 50 mm. Outside diameter D: 80 mm. Single-row assembled width T for the 33010 metric size: 24 mm (ISO series dimension for this designation). Number of rows per set: 2. Cage: pressed steel (J). Precision class: P5 (ISO class 5 / ABEC 5). Arrangement: DB, back-to-back, matched with ground spacer. Country of manufacture: Japan.

Interchange guidance

Written variously as HR33010JDBP5+KL7CP45, HR33010J DB P5, HR33010JDB, HR33010J, HR 33010 J, 33010J and 33010. The base ISO size designation 33010 is shared across manufacturers on the 50 x 80 mm envelope; the matched DB P5 set with a ground spacer is a distinct product from loose standard-class single bearings of the same size, with its own precision class and preset preload.