Timken2MM9116WI-SULSuper Precision Angular Contact Ball Bearing 80 x 125 x 22 mm, 15° Contact Angle, ABEC 7/9, Universally Flush Ground Single

Product Description

What this part is

A single Fafnir (now Timken) 2MM9116WI super precision angular contact ball bearing, 80 mm bore × 125 mm outside diameter × 22 mm wide. It belongs to the 9100 extra-light series, ISO 10 series, the 7016 envelope, and is ground to ABEC 7/9 tolerances. This is a machine tool spindle bearing.

Designation breakdown

2: Timken code for a 15° contact angle, written C in ISO. MM: super precision, between ABEC 7 (ISO P4) and ABEC 9 (ISO P2), Timken’s MV grade being plain ABEC 7 / P4 and MM the higher of the two. 9116: 9100 extra-light series, bore code 16, 16 × 5 = 80 mm. WI: angular contact construction with a low shoulder on the outer ring only. SUL: universally flush ground single bearing at light preload, SU being a single, DU a duplex pair and TU a triplex set, with X, L, M and H denoting extra-light, light, medium and heavy preload.

Carton and ring markings

The original Fafnir Super Precision carton label reads 2MM9116 WI, with no preload or matching suffix. The ring etch reads 2MM9116WI, then a short character group that is not fully legible through the sealed factory wrapper, then a C2 manufacturing code and LOT # 688xx. The ring is also marked THRUST. A Fafnir WI Series instruction sheet for duplex universal pairs is packed in the box. One bearing is physically present.

Specifications in application

15° is the low-angle option in this family, giving the highest speed capability and the lowest axial stiffness of the standard angles. The 25° alternative, Timken 3MM and ISO E, trades roughly a tenth of the speed rating for substantially more thrust capacity and axial rigidity. Universal flush grinding lets two or more of these stack directly into a DB, DF or DT set with the ground faces butted, without spacers or measured shims, at the designed preload. ABEC 7/9 provides sub-micron radial and axial runout, which is what holds a bored diameter or a ground finish to tolerance.

Published ratings

From the Timken Fafnir Super Precision Bearings for Machine Tool Applications catalogue (order 5918), 15° steel-ball columns. Basic dynamic radial load rating C: 64,900 N (14,600 lbf). Basic static radial load rating C0: 55,200 N (12,400 lbf). Speed rating (Ng): 10,300 rpm for a single grease-lubricated spring-preloaded bearing. Ball complement: 20 steel balls, 13.5 mm (17/32 in) diameter. Bearing weight: 0.859 kg (1.89 lb). Published duplex data for this size, back-to-back: DUL 310 N preload, 8,200 rpm grease / 13,900 rpm oil; DUM 670 N, 6,200 / 10,500 rpm; DUH 1,560 N, 4,100 / 7,000 rpm. Axial stiffness runs 92.87 N/µm at light preload to 189.59 N/µm at heavy.

Quantity and configuration

One bearing, a single piece rather than a matched pair or set.

Mounting data

Maximum shaft fillet radius: 1.0 mm (0.039 in). Suggested shaft shoulder diameter: 89.3 / 88.5 mm (3.52 / 3.49 in). Suggested housing shoulder diameter: 116.5 / 115.7 mm (4.59 / 4.56 in). Grease fill: 3.85 g (10 %) to 5.80 g (15 %) at high speed, 8.60 g (25 %) to 13.80 g (40 %) at low to moderate speed. The WI construction puts a low shoulder on one side of the outer ring, so the bearing has a defined thrust direction and the marked face carries the load. The phenolic cage standard to this family is rated to about 93 °C (200 °F), the practical temperature ceiling for a grease-packed WI spindle bearing.

Interchange guidance

The 80 × 125 × 22 mm, 15° envelope is ISO 7016C. Same-envelope super precision bearings from other makers, including NSK 7016CTYNSULP4, FAG B7016C.T.P4S, SKF 7016 CD/P4A and NTN 7016CT1DB/GNP4, are dimensionally and functionally comparable, with preload class and cage type matched to the application, and none is a Timken-published interchange. Fafnir is a retired brand name: Fafnir super precision became Timken super precision, so the current-production equivalent is a Timken 2MM9116WI with the applicable preload suffix.