Barden105HEDUMSuper Precision Angular Contact Spindle Bearing Pair 25x47x12 mm ABEC 7 Medium Preload

Product Description

What this part is

A Barden 105HEDUM matched duplex pair of super-precision angular contact spindle bearings. Each bearing has a 25 mm bore, a 47 mm outside diameter and a 12 mm width, giving a 24 mm stack height for the pair. The 105 size shares the 7005 envelope.

Decoding the designation

105 — Barden 100 series, 25 mm bore, 47 mm OD, 12 mm widthH — Barden high-precision spindle execution, ABEC 7DUM — duplex universally ground, medium preload

What these specs mean in practice

Universal grinding is what makes the pair work: the ring faces are finished so any two bearings of this designation clamp together into a matched set and reach the designed preload when the rings are pulled flush, with no shimming. Medium preload gives higher axial and radial stiffness than a light set, so the spindle holds position better under cutting load, and it generates more heat, which sets the practical speed ceiling. ABEC 7 running accuracy keeps radial and axial runout low enough that the preload stays even around the circumference.

Published specifications

Bore: 25 mm (0.9843 in)Outside diameter: 47 mm (1.8504 in)Width per bearing: 12 mm (0.4724 in)Total width as a pair: 24 mm (0.9449 in)Precision class: ABEC 7Preload: medium (M)Number of rows: 1 per bearingRolling elements: steel ballsClosure: openArrangement: duplex universally ground pair

Quantity and configuration

Supplied as 2 Pcs, a matched duplex pair.

Fitting notes

The pair mounts with the ground faces butted and the inner rings clamped so the built-in offset develops the medium preload. Orientation sets the behaviour: back-to-back or face-to-face carries thrust in both directions and resists tilting, while tandem carries thrust in one direction at doubled capacity. The two bearings stay together as a set, since pairing one of them with a bearing from another set changes the preload.

Interchange guidance

Genuine equivalents are ABEC 7 universally ground medium-preload pairs in the same 25x47x12 mm envelope and with the same contact angle: Barden 105H series pairs, and 7005-series super-precision duplex sets from Fafnir, FAG, NSK and RHP in matching angle and preload. Light or heavy preload versions of the same size are related sizes rather than interchanges, because they change spindle stiffness and running temperature.