SKF bearing numbers are a combination of letters, numbers and sometimes symbols that identify the size and type of a bearing. The SKF Group has been using a numbering system for its bearings since 1911.
The first letter in an SKF bearing number indicates the shell diameter in millimeters (mm). For example, if a bearing has an “A” as its first letter, it means that its outside diameter is 85 mm.
The second letter in an SKF bearing number indicates the bore diameter in millimeters (mm). For example, if a bearing has an “E” as its second letter, it means that its inside diameter is 63 mm.
The third letter in an SKF bearing number indicates the width between the inner races in millimeters (mm). For example, if a bearing has an “N” as its third letter, it means that its width between the inner races is 38 mm.
The fourth letter in an SKF bearing number indicates the thickness of its outer ring or housing in millimeters (mm).
The SKF website says that the numbers on a SKF bearing are arranged so that the first number describes the bearing series, and the rest of the numbers describe various aspects of that series.
The first digit indicates the basic design of the bearing, with 1 being a deep groove ball bearing and 2 being an angular contact ball bearing. The second digit indicates what kind of material is used for manufacturing this type of bearing. For example, if it’s a deep groove ball bearing, then it will be made out of steel or cast iron. If it’s an angular contact ball bearing, then it will be made out of steel or aluminum alloy.
The third digit represents a special feature that is included in this particular model of bearing. For example, if there is a “C” in this position, then it means that there is no cage around this kind of bearing and so you can use lubricants other than oil in your machine without worrying about them damaging your bearings as they would if they were enclosed by cages or shields.
The first and second numbers on a bearing describe the characteristics of the bearing, and the third number describes the number of rows of balls.The fourth number describes an adjustment factor.
The first two numbers give an idea about the load capacity of a bearing. The higher these numbers are, the greater is the load capacity of the bearing. For example, if a bearing has a first number of 7 and a second number of 2, then it can carry more load compared to another bearing that has a first number of 7 and second number of 1.
The third number gives us an idea about how many ball rows are there in a single unit cell (a single row). For example, if we have two bearings with same first and second numbers but different third numbers, then one will have more balls per unit cell than other one. This means that one will carry more load than other one for same size or diameter.
The fifth number describes clearance.
It is the distance between the bearing outer ring and the bore of its housing in thousandths of an inch or millimeters. A large clearance allows for expansion of a shaft during operation. A small clearance is used where there is a need to minimize shaft deflection under load, such as in pump bearings. A bearing with a fifth digit of 1 has a normal clearance. A bearing with a fifth digit of 2 has a slightly larger clearance than normal, while a bearing with a fifth digit of 0 has no clearance at all.
The sixth through eight numbers describe the diameter in millimeters.
For example, a 6204 bearing has a 6mm outside diameter and an inside diameter of 4mm. The final two numbers indicate the width of the bearing, in this case 0.2mm.
The last number is usually used to identify the bearing’s series, such as whether it’s made of chrome steel or bronze, or if it has needle bearings or ball bearings.
In addition to size and material, SKF also makes different types of bearings with different load ratings.
SKF bearings have lots of numbers on them but they have specific meanings.
The first digit is the series, which identifies the basic design of the bearing. The second set of numbers is the bore diameter in millimeters and lastly there are two more digits that indicate the width of the bearing in millimeters.
The last four digits are the serial number of the individual bearing.SKF has a variety of different bearing types available, with different features to suit different applications. The most common types are:
Deep groove ball bearings – this type of bearing is widely used in both general industrial use and automotive applications. They feature wide inner and outer raceways with straight grooves and a single row casing. Deep groove ball bearings can be used in both radial and axial directions and provide high rigidity. They also offer high speed rotation capability and good stability at high speeds due to their low friction levels. In addition, deep groove ball bearings have low noise levels for quieter operation compared to other types of bearings.
Self-aligning roller bearings – this type of bearing has a cylindrical outer ring that allows it to self-align during operation so as not to require additional preload as it rotates at high speeds or under heavy loads which would otherwise result in damage.
SKF Bearings have a unique method for identifying their bearings by using a three letter code as a prefix to their part number. This code tells you what kind of bearing you have and what its main application is. For example, if you have an FAG bearing, it will be used in applications like automotive engines or turbines where high speed is necessary and maximum load capacity required.
SKF bearings are stamped with a unique serial number, or “dimensional code.” This system was developed in the late 1920s and currently has three, four or five components. SKF’s own code systems have evolved over time but remain consistent world-wide and can easily be deciphered by looking up the code, or in some cases by simply reading the numbers.