What Does ZZ Mean On A Bearing?

What is the difference between 2rs and ZZ bearings?

The 2RS are sealed for life bearings i.e.

the grease within the bearing cannot get out or contaminants get into the bearing and damage it.

The ZZ are just a metal shield to stop larger contaminants damaging the bearing..

What do the letters mean on bearings?

The number and letter combinations have the following meaning: The first digit or letter or combination of letters identifies the bearing type and eventually a basic variant. … The first digit indicates the width or height series (dimensions B, T or H). The second digit identifies the diameter series (dimension D).

What does UU mean on a bearing?

U – means single seal; UU – Represents double seals. Unmarked – means not sealed; Therefore,please describe exactly for each bearing you need.

How do I know if my bearings are sealed?

If the bearing number uses the AFBMA code, look for “EE” (or “2RSI” for SKF) to determine if the bearing is sealed on both sides. This is the only way to identify whether a bearing is sealed. Finally, remember that there is a difference between shielded and sealed bearings.

Are Sealed bearings better?

Sealed cartridge bearings however come complete as an enclosed unit. … We use sealed so the bearings are protected from road debris and weather, so they spin cleaner and with less friction for longer. Sealed bearings perform as well or better than loose bearings, without the maintenance.

Do sealed bearings need to be greased?

Bearings need grease for one reason only, to reduce friction. As long as the lubricant is performing that service well, there should be no need to change it, or add more. Yet we frequently do, with catastrophic results.

Can bearings be over greased?

Too much grease volume (overgreasing) in a bearing cavity will cause the rotating bearing elements to begin churning the grease, pushing it out of the way, resulting in energy loss and rising temperatures. … This can result in accelerated wear of the rolling elements and then component failure.

How long do Sealed bearings last?

eight to 12 yearsWhile circumstances vary, best practices suggest bearings should last eight to 12 years if properly maintained.

Can you put sealed bearings in an unsealed hub?

New Member. It wont work. Open bearing hubs are machined so the bearing race is the hub body itself, which is rounded so the bearings roll on the hub in the machined race. Sealed hubs are machined with square recesses for the sealed cartridge to be press fitted into the hub shell.

What are the two types of seals used on bearings?

Let’s break down the different types of seals available for your bearing products.Contact Seals. A contact seal, also known as a lip seal, is a rubber part (typically Buna-N and nitrile) bonded to a steel insert. … Non-contact seals. … Labyrinth Seals. … Identify the Right Seals for Your Bearings.

What is better sealed or shielded bearings?

“Shields are metallic and there is no contact between the shield bore and the bearing inner ring. … “However, while contact seals provide better protection against contamination there is an increase in rotational torque due to friction between the seal lip and bearing inner ring.

Are ZZ bearings sealed?

Bearings are provided with shields / seals on bothsides to retain factory filled lubricant. Bearings with steel shields are termed as ZZ as suffix after their designated number. Example 6200 bearing is open type bearing, where as 6200-ZZ bearing is shielded and 6200-Z is one side shielded, one side open bearing.

What are the purpose of bearings and seals?

The primary functions of a bearing seal are to keep lubricant in the bearing and bearing chamber contaminants out. Some seals are integral to the bearing; others aren’t.

Are NTN Bearings any good?

In testing the NTN bearings are generally the best irrespective of which seal is put on them. Their technical support is also very good (especially in the UK). The vast majority of NTN’s 6000 series bearings are made in Japan and they are sticklers for quality control. The only issue with NTN is supply.

What does c3 mean on a bearing?

Internal clearanceInternal clearance being C3 means that the bearing has room for expansion if needed between the races of the bearing, whilst holding the outer ring and moving the inner ring in a radial movement you will detect a little amount of play between the two rings.