How to Read FAG Codes: Designation Structure, Prefixes, Suffixes, and Real Examples

FAG bearings are identified by a standardized designation system that combines numbers and letters. This code is not arbitrary: each part provides information about the bearing type, its main dimensions, and design or material features. For a maintenance manager, knowing how to read it is key when replacing a part or requesting a quote.

MR Accesorios Industriales sells FAG bearings in Buenos Aires, Argentina. We work with a wide variety of references, from special bearings to spherical, cylindrical, and tapered rollers. If you have the part code, we'll quote it for you without hassle.

The designation of a FAG bearing usually consists of a base code, which identifies the type and size, and prefixes and suffixes that indicate design, material, or treatment variants. For example, in a deep groove ball bearing, the base code can be a four-digit number like 6205, where the 6 indicates the type (deep groove ball) and the following digits define the dimensional series and bore diameter.

In the case of tapered rollers, the base code can be a number like 33115, where the series 331 corresponds to a tapered roller bearing of a metric inch and the 15 indicates the bore diameter in millimeters (15 x 5 = 75 mm). This logic is repeated in other series, but it is always advisable to verify with the manufacturer's catalog.

Prefixes are placed before the base code and usually indicate a design variant or a special series. For example, the prefix SL is used in cylindrical roller bearings of the light series, such as in SL182226 or SL183018. These bearings have specific load capacity and cage design characteristics.

Another frequent prefix is ZM, which appears in special bearings such as ZM85 or ZM70. In general, these prefixes identify bearings for particular applications, such as spindle supports or high-precision units. If you find a code with a prefix and are not sure of its meaning, you can consult us with the complete code.

Suffixes are added at the end of the base code and provide information about the internal design, seals, cage, or radial clearance. For example, the suffix 2RS indicates that the bearing has two rubber seals, one on each side, making it suitable for dusty or humid environments. The suffix C3 indicates a radial clearance greater than normal, useful when there is thermal expansion.

In spherical roller bearings, the suffix MB is common, indicating a machined brass cage. For example, in 20222-MB or 20240-MB, the suffix MB indicates that type of cage. In tapered rollers, suffixes can indicate the contact angle or cage design, although in many cases the base code already defines the bearing.

It is important not to confuse suffixes with the base code. If you have doubts about a specific suffix, you can send us a photo of the part or the complete code and we will help you identify it.

To show you how the nomenclature is applied, here are some codes we sell at MR Accesorios Industriales:

Spherical rollers: 20222-MB, 20240-MB, 24896-MB. The series 202 or 248 indicates the type and dimensions, and the suffix MB the brass cage.

Cylindrical rollers: SL182226, SL183018, SL183036. The prefix SL indicates light series, and the following numbers define the size.

Tapered rollers: 33115, 32915, 32326. Each number corresponds to a specific series and diameter.

Withdrawal sleeves: AH211, AH209, AH308. These accessories are used to mount bearings with a tapered bore.

Special bearings: ZM85, ZM75, ZM70. These are less common references, but we can quote them if you need them.

When you need to replace a FAG bearing, the most practical thing is to have the complete code on hand, as it appears on the part or on the equipment plate. With that data, you can write to us via WhatsApp or email and we will quote the exact reference. If the bearing is very damaged and the code cannot be read, you can send us a photo and the main dimensions (inner diameter, outer diameter, and width) to identify the alternative.

At MR Accesorios Industriales we work with FAG bearings and other brands, and we help you find the correct part for your application. Do not hesitate to consult us about any reference, even the less common ones.

Reading FAG codes is a valuable skill for any maintenance professional. Knowing the structure of the designation, prefixes, and suffixes allows you to quickly identify the bearing you need and avoid ordering errors. At MR Accesorios Industriales, based in Buenos Aires, Argentina, we offer advice and quotes for FAG bearings for all types of industries.

If you have a FAG code on hand, write to us via WhatsApp or email and we will quote it promptly. You can also send us a photo of the part if you are not sure of the code. We are here to help you keep your equipment running.