A, B, C, D, E, when normal internal structure change, the rear part of the code and its composing general SKF bearing http://www.alierbearings.com/brand/skf/index.html  series code, they are usually only used in the transitional period, namely omit no after the transition period.
However, when they represent an alternative structure, these postcodes become permanent.
Usually their meanings are specific to a bearing type or bearing series.
Such as:
Single row Angle contact ball bearing
ACD - contact Angle is 25 degrees.
B -- the contact Angle is 40 degrees.
CC -- the contact Angle is 12 degrees.
CD -- the contact Angle is 15 degrees.
BE - contact Angle of 40 degree BE type bearing, steel ball increased, glass fiber reinforced nylon 6.6.
Double row Angle contact ball bearing
A - the standard design of the outer diameter is less than or equal to 90 mm bearing, without the ball gap, the glass fiber reinforced nylon 6.6 is adopted.
E - the SKF bearing side of the bearing has the ball port, which can hold more steel ball, so it has higher radial and axial bearing capacity.
CAC, ECAC, CA, ECA - these are designed for large - sized bearings with symmetric rollers.
Both sides of inner ring have fixed baffle, and the inner ring is guided by inner circle.
Keep the frame as an integral brass or steel frame.
CAC and ECAC bearing roller and raceway surface are optimized to help roller guide and reduce friction.
The ECAC type has reinforced roller to improve load capacity.
CC, C, EC -- this kind of SKF bearing roller is symmetrical and has no edge in the inner loop.
Each roller has a ramming plate holder.
The retaining ring in the activity is guided by inner ring.
The EC type SKF bearing is used to strengthen the roller to improve load capacity.
CC bearing roller and raceway surface are optimized to help roller guide and reduce friction.
E - the SKF company using the latest standard design, bearing roller symmetry, inner ring no guard, iron ring close to the outer ring made of bronze, guided by cage, each column roller has a stamping steel cage.
The type E SKF bearing has all the advantages of CC bearing, and the latest development of the retaining rack can be put into more and larger diameter extended rollers to make bearing load capacity higher.
Type E bearing outer ring with oil tank and three oil holes.
Cylindrical roller bearing
B - bearing surface treated rollers (full roller bearing).
B4 - bearing ring surface and roller surface are processed (full roller bearing).
EC -- the internal geometry of the bearing is improved, with high bearing capacity, good contact and lubrication condition on the edge and roller side, which can withstand higher axial load.