Fafnir3MM9107WI DUMSuper-Precision Angular Contact Ball Bearing Duplex Pair — 35 mm Bore, 62 mm OD, 14 mm Wide, 25° Contact Angle, Medium Preload, Phenolic Cage

Product Description

What this part is:

Fafnir 3MM9107WI-DUM super-precision angular contact ball bearing, supplied as a matched duplex pair. Bore Diameter: 35 mm. Outside Diameter: 62 mm. Overall Width: 14 mm per bearing. Series: 9100WI. Base Number: 9107. Rolling Elements: Ball. Bore Type: Straight. Closure Type: Open. GTIN: 087796072251. The 9107 size code is the ISO 7007 envelope.

Decoding the designation:

3MM — Contact Angle: 25°, in Timken’s MM super-precision spindle range.

MM — Precision Class: ABEC 7/9 (P4S).

9107 — the 35 mm bore size in the 9100 light spindle series, on ISO 7007 boundary dimensions.

WI — low shoulder on both rings.

DU — Mounting Arrangement: duplex, two bearings ground as one matched set.

M — Preload: Medium.

What these specs mean in practice:

Dynamic Load Rating: 20,200 N. Static Load Rating: 13,000 N. Contact Angle: 25°. A 25° angle carries more thrust and less speed than a 15°, which is why the steeper angle is chosen where the axial component dominates.

Limiting Speed: 22,300 rpm grease; 40,600 rpm oil. Preload: Medium. Precision Class: ABEC 7/9. Cage Material: Phenolic, light and quiet at high surface speeds. Medium preload raises axial and radial stiffness above the light setting at the cost of some speed headroom.

Mounting data:

Shaft backing shoulder diameter 40.6 mm. Housing backing shoulder diameter 56.6 mm. Maximum housing fillet radius 1 mm. The straight bore seats on a ground spindle journal, and the universally ground faces set the preload when the clamp nut is tightened.

Quantity and configuration:

Unit Quantity: 2 Pcs. Number Of Rows: 2. Two bearings ship as one factory-matched DUM set.

Interchange guidance:

The 35 x 62 x 14 mm envelope at 25° is the ISO 7007 A5 size, so a 25° super-precision 7007 duplex set at medium preload from another maker fits the same seat. The Fafnir 2MM9107WI-DUM shares the envelope at 15° and is listed as a related angle rather than an interchange.