Fafnir2MM9516WISuper Precision Spindle Angular Contact Ball Bearing 80 mm Bore, 15 Degree Contact Angle, ISO P4S – Outside Diameter and Width To Be Confirmed

Product Description

What this part is

A Fafnir super-precision spindle angular contact ball bearing with an 80 mm bore, 15° contact angle, from the MM-prefix machine tool range. Fafnir is now part of Timken.

Decoding the designation

2MM is Timken’s designation for a super-precision spindle bearing at the low contact angle, 15°: Timken’s catalogue states that 2 is the Timken designation and C the ISO designation for 15°. 16 is the bore code, 80 mm, confirmed across every WI series Timken publishes. WI is the angular contact geometry: full shoulders on both sides of the inner ring and a low shoulder on the outer, thrust in one direction, non-separable. The MM prefix carries ISO P4S precision: running accuracy and performance to ABEC 9 (ISO P2) levels, with other features to ABEC 7 (ISO P4).

What a 15° angle means in practice

15° biases the bearing toward radial load and speed. It runs cooler than a 25° bearing at equal rpm, holds radial running accuracy better and reaches a higher limiting speed, which is why grinding spindles and high-speed machining spindles specify it. The trade-off is axial capacity and axial stiffness. Angles must be matched across a spindle stack. Contact Angle: 15°. Precision Class: P4S.

Quantity and configuration

1 Pc.

Interchange guidance

This 80 mm bore, 15°, P4S envelope is closely related to two Fafnir/Timken world-number designations: 2MM9116WI, ISO equivalent 7016C-T-P4S, envelope 80 x 125 x 22 mm; and 2MM9316WI, ISO equivalent 71916C-T-P4S, envelope 80 x 110 x 16 mm. These are different bearings with different ratings. Barden’s 116-series bearing occupies the same 80 x 125 x 22 envelope as 7016C. Fafnir spindle bearings are now branded Timken.