NSKHR30309DJDBP5Tapered Roller Bearing Pair – 45 mm Bore, 100 mm OD, 27.25 mm Width, 28° Steep Contact Angle, Back-to-Back, P5

Product Description

What this part is:

NSK HR30309DJ steep-angle single-row tapered roller bearing, supplied as a back-to-back matched pair with spacers. Bore Diameter: 45 mm. Outside Diameter: 100 mm. Overall Width: 27.25 mm per bearing (T). Cone width B: 25 mm. Cup width C: 18 mm. Contact Angle: 28°. Rolling Elements: Tapered Roller. Number Of Rows: 1 per bearing. Bore Type: Straight. Closure Type: Open. Cage Material: Pressed steel. Series: 303. Base Number: 30309. Mounting Arrangement: Back-to-back (DB). Unit Quantity: 2 Pcs.

Decoding the designation:

HR — NSK high-capacity tapered roller execution, uprated roller complement over the plain 30309.

30309 — ISO 303 dimension series, bore code 09, giving a 45 mm bore in a 100 mm outside diameter.

D — steep contact angle, about 28°, against roughly 11° 30′ on the plain 30309.

J — pressed steel cage.

DB — back-to-back matched pair.

P5 — ISO class 5 running accuracy, RBEC 5.

KL20 — the inner and outer ring spacer set marked on the carton.

What these specs mean in practice:

Dynamic Load Rating: 118,000 N per bearing. Static Load Rating: 109,000 N per bearing. Limiting Speed: 3,400 rpm grease; 4,800 rpm oil. Item Weight: 0.957 kg (2.11 lb) per bearing. Precision Class: RBEC 5 / P5. Contact Angle: 28°.

The 28° angle is roughly two and a half times the standard 303-series angle, so this execution converts a much larger share of its capacity into axial rating. Mounted back-to-back the pair sets a wide effective load span, which is what gives a shaft its resistance to tilting moments. P5 tightens bore, outside diameter and both radial and axial runout beyond the normal class, which is what a machine tool or gearbox input shaft is buying.

Mounting data:

Axial load factors: e 0.83, Y0 0.40, Y1 0.73. The KL20 spacer pair sets the mounted preload across the back-to-back set. Cone and cup separate for mounting, so the inner ring goes on the shaft and the cup into the housing independently.

Quantity and configuration:

Unit Quantity: 2 Pcs. Two complete cone-and-cup bearings, matched as a back-to-back set, with the KL20 spacers.

Interchange guidance:

Steep-angle 303xxD equivalents at the same 28°: NTN 30309D, Koyo 30309DJR, Nachi 30309D. SKF 30309 J2/Q, FAG 30309-A, Timken 30309 and RHP 30309 share the 45 x 100 x 27.25 mm envelope but run the standard 303-series angle of roughly 11° 30′, which changes the axial rating — those are related sizes rather than direct substitutions.