FafnirMM214KSpindle Deep Groove Ball Bearing — 70 mm ID, 125 mm OD, 24 mm Width, Phenolic Inner Land Riding Cage, ABEC 7/9

Product Description

What this part is

Fafnir MM214K, a single-row super-precision spindle deep groove ball bearing from Timken’s Fafnir 200K range. Bore: 70 mm. Outside Diameter: 125 mm. Overall Width: 24 mm. Precision Class: ABEC 7/9 (ISO P4S). Cage Type: CR, phenolic inner land riding. Cage Material: phenolic. Rolling Elements: steel balls. Number of Rows: 1. Design Units: Metric. Manufacturer Part Number: MM214K.

Decoding the designation

MM — Fafnir super-precision spindle execution, ground to ABEC 7/9 (ISO P4S) tolerance.

214 — 200 medium dimension series, bore code 14. That is the ISO 6214 envelope: 70 mm bore, 125 mm outside diameter, 24 mm width.

K — the 200K spindle deep groove family: Conrad deep groove geometry built and gauged to spindle standards.

What these specs mean in practice

Dynamic Radial Load Rating (C1): 69,000 N (15,500 lbf). Dynamic Radial Load Rating, ISO method (C1 per row): 62,700 N (14,100 lbf). Static Radial Load Rating (C0): 43,600 N (9,800 lbf). Limiting Speed, grease: 10,500 rpm. Limiting Speed, oil: 21,000 rpm.

A deep groove bearing takes radial load and axial load in either direction, so one of them can locate a shaft in both directions on its own. That is the difference from an angular contact bearing of the same bore, which carries thrust one way and needs a partner. Building it to ABEC 7/9 is what makes it usable at the drive end of a grinding or milling spindle: the raceway and bore tolerances hold the running accuracy while the deep groove geometry does the bidirectional location.

The phenolic cage rides on the inner ring lands, so it is centred by the faster-moving ring. Phenolic is light, runs quiet, and the resin holds oil in its own porosity to feed the ball pockets.

Quantity and configuration

Unit Quantity: 1 Pc. One single-row bearing.

Mounting data

Shaft Backing Shoulder Diameter: 80.3 mm (3.160 in). Housing Backing Shoulder Diameter: 115.8 mm (4.560 in). Maximum Shaft Fillet Radius: 1.5 mm (0.059 in). Outer Ring To-Clear Radius: 1.5 mm (0.059 in).

Interchange guidance

Cross-Reference: ISO 6214 envelope. Searchable variants of the Fafnir number: MM214K, MM-214-K, MM 214 K, MM214KCR, 6214-T-P4, 214K.

A commercial 6214 shares the 70 x 125 x 24 mm envelope. The MM214K differs in grinding class and cage: ABEC 7/9 against standard tolerance, and a phenolic inner land riding cage against a pressed steel one.