FafnirMM205KPrecision Spindle Deep Groove Ball Bearing – Straight Bore, 25 mm ID, 52 mm OD, 15 mm Width, Open, Machined Phenolic Cage, P4S

Product Description

What this part is

Fafnir MM205K precision spindle deep groove ball bearing, built by The Timken Company. Bore: 25 mm. Outside Diameter: 52 mm. Overall Width: 15 mm. Bore Type: Straight. Number Of Rows: 1. Rolling Elements: Balls. Closure Type: Open. Cage Material: Phenolic. Cage Type: Machined. Precision Class: P4S, ABEC 7/9. Series: 200K spindle series. Bearing Material: Bearing steel. Dynamic Load Rating: 14.8 kN / 3330 lbf. Static Load Rating: 7.8 kN / 1750 lbf. Limiting Speed: 24,000 rpm. Item Weight: 0.28 lbs. Unit Quantity: 1 Pc.

Decoding the designation

MM: Fafnir’s super precision spindle prefix, carrying Precision Class P4S. 205: 25 mm bore in the 200 series. K: the spindle deep groove execution within the 200K family. The 200K, 300K and 9100K families are spindle deep groove ball bearings, and the 25 x 52 x 15 mm envelope is the 6205 section. Searchable variants: MM205K, MM 205 K, MM-205-K, MM205.

What these specs mean in practice

A deep groove raceway carries radial load with modest thrust capacity in either direction from a single row, and it runs faster than an angular contact bearing of the same size because there is no fixed contact angle to load the balls axially. P4S tolerances hold bore, outside diameter and raceway runout to spindle-grade bands, so shaft position stays repeatable. The machined phenolic cage is light and quiet, holds a small reservoir of oil in the resin and sets a 120 °C continuous ceiling. Open on both faces, so the bearing takes its lubricant from the spindle system, which suits grease, oil-mist and oil-air feeds.

Quantity and configuration

Unit Quantity: 1 Pc. One single bearing, open on both faces.

Fitting notes

The 25 x 52 x 15 mm envelope drops into any housing bored for a 6205 section. Straight bore, so the inner ring seats directly on a cylindrical shaft journal. Operating temperature range: -30 °C to 120 °C.

Interchange guidance

Same envelope in a precision execution: SKF 6205/P4 and NSK 6205T12TP4. A 7205 angular contact bearing shares the 25 x 52 x 15 mm envelope but carries a fixed contact angle, which makes it a related size rather than a substitute.