NSKHR30308DJP5Tapered Roller Bearing Cone and Cup Set — 40 mm Bore, 90 mm OD, 25.25 mm Width, Steep 28° Contact Angle, High-Capacity HR, P5 Precision

Product Description

What this part is

NSK HR30308DJP5, a complete single-row metric tapered roller bearing — cone, roller and cage assembly plus its matched cup. Bore: 40 mm. Outside diameter: 90 mm. Assembled width T: 25.25 mm. Series: 30300. Contact angle: 28°. Precision: P5. Country of origin as recorded: Japan.

Decoding the designation

HR: NSK’s high-capacity execution, an uprated internal geometry within the standard boundary dimensions. 30308: the ISO metric tapered roller series and size. D: steep contact angle, approximately 28°. J: pressed steel cage. P5: ISO Class 5 accuracy, ABEC 5 — tighter running and dimensional tolerance than a standard-class bearing, giving closer shaft location and lower runout.

Ratings and speed

Basic dynamic load rating Cr: 98.0 kN (22,000 lbf). Basic static load rating C0r: 89.5 kN (20,100 lbf). Limiting speed: 3,800 rpm on grease, 5,300 rpm on oil, 8,000 rpm on mechanical jet lubrication. Axial load factor e: 0.83. Y0: 0.4. Y1: 0.73. Effective load centre a: 28.7 mm. Mass: 0.728 kg.

What these specs mean in practice

The D contact angle is the point of this bearing. At roughly 28° against the 12 to 16° of a standard 30308, it carries a far higher proportion of thrust for the same envelope, which shows up in the e factor: 0.83 here against roughly 0.35 on a standard-angle 303 section. That is the ratio of axial to radial load at which thrust starts to govern the equivalent load calculation, so a high e means the bearing tolerates a heavily axial duty before the calculation changes character. The trade is a shorter effective load centre spread and a different mounting stiffness.

Quantity and configuration

One complete bearing: the cone assembly and its matched cup, supplied together. Tapered rollers are separable by design, so the two halves are matched and ground as a unit.

Fitting notes

Cone width B: 23 mm. Cup width C: 17 mm. Shaft backing shoulder da: 56 mm, db: 50 mm. Housing shoulder Da: 70 to 81 mm, Db: 87 mm. Both faces are open. Axial location and running clearance are set at assembly by the shoulder positions rather than built into the bearing.

Interchange guidance

Closest match: NSK HR30308DJ, the same steep-angle bearing at normal precision rather than P5. SKF 31308 J2/QCL7C is a steep-angle bearing of the same size at normal precision. SKF 30308 J2/Q, FAG 30308-A and NSK HR30308J share the boundary dimensions but run a standard contact angle at normal precision, so they carry much less thrust. The searchable forms include HR30308DJP5, HR-30308-DJ-P5, HR 30308DJ P5, 30308DJP5 and 30308D.