SNFAEX55-7CE1DUMSuper-Precision Angular Contact Ball Bearing – 55 mm ID, 90 mm OD, 18 mm Width, Open, 15 Degree, Medium Preload Universal Duplex Set of 2

Product Description

What this part is

SNFA EX55-7CE1DUM super-precision angular contact ball bearing, supplied as a universally ground duplex set of two. Bore 55 mm, outside diameter 90 mm, width 18 mm per bearing, 36 mm across the mounted pair. Open on both faces, phenolic window cage, chrome bearing steel rings and balls. The ISO equivalent base number is 7011.

Decoding the designation

The bore code 55 gives the 55 mm bore. The 7 is the precision class, ABEC 7 / ISO P4. CE denotes the high-speed super-precision execution with a phenolic outer-land-riding cage. The trailing 1 carries the contact angle at 15°. DUM is a universal duplex pairing at medium preload.

What these specs mean in practice

A 15° contact angle favours speed and radial stiffness over thrust capacity, which suits machine tool spindles, grinding heads and high-speed ball screw ends. Dynamic load rating 40.5 kN, static load rating 34 kN, limiting speed 11,000 rpm. The phenolic cage is light and tolerant of high speed with oil-air or light grease lubrication, with a practical upper temperature around 120 °C.

Quantity and configuration

Two bearings, universally ground so the pair can be arranged back-to-back, face-to-face or in tandem, developing medium preload in any of those arrangements. Being preloaded, the set carries no radial internal clearance value.

Fitting notes

Straight bore on an interference fit shaft seat, outer rings located in a bored housing. The two rings are matched and ground as a unit at the factory and stay together. Preload comes from the ground ring offset, so no shim stack is required.

Interchange guidance

Same-specification equivalents at 15° and P4 in this envelope are the FAG B7011-C-T-P4S-DUM and the SKF 7011 CD/P4A DGB. A 7011 in a 25° execution shares the 55 x 90 x 18 mm envelope but is a related size rather than an interchange, because the contact angle changes the thrust and speed balance.