Fafnir2MM307WIDULSuper-Precision Angular Contact Ball Bearing Pair – 35 mm Bore, 80 mm OD, 21 mm Width, 15°, Light Preload

Product Description

What this part is

Fafnir 2MM307WICRDUL, a super-precision angular contact ball bearing supplied as a universally ground duplex pair. Bore Diameter: 35 mm. Outside Diameter: 80 mm. Overall Width: 21 mm per bearing. Total Width: 42 mm mounted as a pair. Contact Angle: 15°. Rolling Elements: Ball. Number Of Rows: 1 per bearing. Bore Type: Straight. Closure Type: Open. Cage Material: Phenolic. Precision Class: ABEC 7/9 / P4S. Preload: Light. Series: 300WI. Base Number: 2MM307WI. GTIN: 087796071506.

Decoding the designation

2MM — Fafnir super-precision spindle range at a 15° contact angle, ground to ABEC 7/9 (P4S) tolerances.

307 — 300 heavy dimension series, bore code 07: a 35 mm bore in an 80 mm outside diameter.

WI — low shoulder on both rings, which is what allows the ball complement and the thrust capacity of this execution.

CR — phenolic cage.

DUL — duplex pair, universally ground, light preload. Either face can be brought together, so the pair mounts back-to-back, face-to-face or in tandem and reaches its rated preload when the faces are clamped.

What these specs mean in practice

Dynamic Load Rating: 46,200 N per bearing. Static Load Rating: 25,600 N per bearing. Timken publishes the same C1 and C0 figures on the single 2MM307WICR page and on this duplex page, and doubles only the mass, so both ratings here are per-bearing values rather than set values. Limiting Speed: 19,200 rpm grease; 38,400 rpm oil. Item Weight: 0.886 kg (1.96 lb) for the pair, 0.443 kg (0.98 lb) per bearing. Internal Clearance: N/A — a preloaded set is clamped to a defined stiffness rather than run to a clearance. A 15° contact angle favours speed and radial rigidity; a 25° execution on the same envelope trades some speed for thrust capacity. Light preload keeps heat generation down on a spindle that runs continuously.

Mounting data

Shaft Backing Shoulder Diameter: 43.2 mm. Housing Backing Shoulder Diameter: 72.1 mm. Maximum Housing Fillet Radius: 1.5 mm (0.059 in) — the largest housing corner radius the bearing corners will clear.

Quantity and configuration

Unit Quantity: 2 Pcs. One universally ground duplex pair. The 21 mm figure is the width of a single bearing; the pair occupies 42 mm of shaft length when clamped together.

Interchange guidance

Direct super-precision equivalents on the 7307 envelope at 15° with light preload: FAG B7307-C-T-P4S-UL, SKF 7307 CD/P4ADGA, NSK 7307CTRDULP4, NTN 7307UCG/GNP4, RHP 7307CTDULP4 and Koyo 7307C P4 DUL. An MRC 307R shares the 15° angle but uses a counterbored outer ring, so treat it as a related design. A standard-tolerance 7307-C shares the envelope and angle only. Searchable variants include 2MM307WIDUL, 2MM-307-WI-CR-DUL, 2 MM 307 WI CR DUL and 2MM307WICRDUL.