RHP6310TBR12P4Deep Groove Ball Bearing – Straight Bore, 50 mm ID, 110 mm OD, 27 mm Width, Open, ABEC 7 / P4 Precision, Machined Phenolic Cage.

Product Description

What this part is

RHP 6310TBR12P4 single-row deep groove ball bearing, ground to super-precision tolerances for machine tool spindle service. Bore Diameter: 50 mm. Outside Diameter: 110 mm. Overall Width: 27 mm. Rolling Elements: Ball. Number Of Rows: 1. Bore Type: Straight. Closure Type: Open.

Decoding the designation

6310 — ISO 63 dimension series, bore code 10. Bore 50 mm, outside diameter 110 mm, width 27 mm. A deep groove bearing takes radial load and axial load in both directions on a single row of balls running in deep, closely conforming raceway grooves.

TB — one-piece machined laminated phenolic cage, centred on the inner ring. Cage Material: Phenolic. Cage Type: Machined one-piece, inner-ring centred.

P4 — ISO tolerance class 4. Precision Class: ABEC 7 / P4.

MM-310-K — the Fafnir designation for the same bearing, carried on the carton. In the Fafnir scheme MM is the P4 tolerance class, the 300K series is the spindle deep groove range, and the CR on the full string MM310KCR is the phenolic cage. Three separate markings therefore agree on a P4 deep groove bearing with a phenolic cage.

What these specs mean in practice

Class 4 grinding holds bore, outside diameter, width and running accuracy to roughly a quarter of the standard-class tolerance band, which is what keeps spindle runout and running vibration low. Dynamic Load Rating: 68,000 N. Static Load Rating: 38,500 N. Ball Diameter: 19.05 mm. Series: 6300. Item Weight: 1.06 kg (2.34 lb).

Laminated phenolic is roughly a seventh the density of brass, so cage inertia and the centrifugal load on the cage pockets stay low at spindle speeds, and the material holds a film of oil in its own structure. Inner-ring centring keeps the cage located by the faster-moving ring.

Mounting data

Chamfer dimension r min: 2 mm. Shaft abutment diameter da: 59 mm min, 68 mm max. Housing abutment diameter Da: 101 mm max. Maximum fillet radius on the shaft or housing ra: 2 mm.

Cross-reference guidance

Same 50 x 110 x 27 mm envelope. Timken MM310KCR and Fafnir MM310K are the same spindle bearing at the same tolerance class. SKF 6310, FAG 6310, NSK 6310, NTN 6310 and Koyo 6310 share the envelope but are standard tolerance class, not P4.