SKF W 608 ZZ 8x22x7 Stainless Steel Deep Groove Ball Bearing

What Is the SKF W 608 ZZ Bearing?

SKF W 608 ZZ is a single-row stainless steel deep groove ball bearing with dimensions 8x22x7 mm and metal shields on both sides. The W prefix identifies SKF metric stainless steel deep groove ball bearings, making this version suitable for applications where improved corrosion resistance is required. SKF documentation confirms that the W designation specifically identifies stainless steel construction.

Technical Specifications

Manufacturer: SKF

Designation: W 608 ZZ

Bearing type: Deep groove ball bearing

Design: Single row

Material execution: Stainless steel

Bore diameter d: 8 mm

Outside diameter D: 22 mm

Width B: 7 mm

Dimensions: 8x22x7 mm

Bore type: Cylindrical

Rolling elements: Balls

Protection: Metal shields on both sides

Lubrication: Grease

Primary feature: Increased corrosion resistance

The standard 608 dimensional series uses an 8 mm bore, 22 mm outside diameter and 7 mm width.

What Does W Mean in SKF W 608?

The W prefix is technically significant.

According to SKF's designation system:

W = stainless steel deep groove ball bearing, metric series.

This differentiates W 608 from a conventional 608 bearing made from standard bearing steel.

The W designation should therefore be retained when selecting a replacement for an application requiring stainless steel construction.

What Does ZZ Mean?

ZZ is commonly used in the bearing market to describe an execution with metal shields on both sides.

In SKF's current designation system, double-sided shields are generally identified by 2Z, while SKF's stainless steel documentation also lists 2ZS for a pressed sheet steel shield on both sides with a retaining ring.

For this reason, when identifying an exact SKF replacement, the designation physically marked on the bearing and its packaging should be checked.

Shielded Bearing Design

Metal shields protect the internal components of the bearing while maintaining low running friction.

Their main functions include:

• limiting the ingress of contaminants,
• retaining lubricant inside the bearing,
• protecting balls and raceways,
• providing non-contact protection suitable for higher-speed operation.

SKF describes the standard 2Z shielded construction as non-contact sealing.

Stainless Steel Construction

The key feature of SKF W 608 is its stainless steel construction.

SKF developed its stainless steel deep groove ball bearing range for applications where conventional bearing steel may be susceptible to corrosion. This makes stainless versions particularly relevant in wet, humid and corrosive operating environments.

Corrosion Resistance

Compared with a conventional 608 bearing, the W execution provides increased resistance to corrosion.

This can be particularly useful in equipment exposed to:

• moisture,
• water,
• frequent cleaning,
• humid production environments,
• corrosive operating conditions,
• applications requiring stainless steel components.

The actual suitability of the bearing must still be evaluated against the specific chemicals, temperature and operating environment.

Deep Groove Ball Bearing Design

SKF W 608 belongs to the single-row deep groove ball bearing family.

Deep groove ball bearings are primarily designed to accommodate radial loads but can also carry axial loads in both directions.

The compact 8x22x7 mm dimensions make the 608 series particularly suitable for smaller rotating assemblies where limited installation space is available.

W 608 vs Standard 608

Both versions use the same principal dimensions:

Bore: 8 mm

Outside diameter: 22 mm

Width: 7 mm

The important difference is material execution:

608: conventional bearing steel version

W 608: stainless steel version

Therefore, dimensional compatibility alone does not mean that a standard 608 is an equivalent replacement for W 608.

W 608 ZZ vs W 608 Sealed

A shielded and sealed W 608 can have identical mounting dimensions but different protection and friction characteristics.

ZZ / 2Z: metal shields

2RS / SKF sealed suffix: sealing elements on both sides

Shielded bearings generally provide low-friction protection, while sealed versions are selected when greater protection against contamination is required.

The correct version should correspond to the original machine specification.

Typical Applications

SKF W 608 stainless steel bearings can be used in suitable:

• small electric motors,
• pumps,
• measuring equipment,
• compact drives,
• conveyors,
• packaging machinery,
• food processing machinery,
• equipment exposed to moisture,
• industrial mechanisms,
• corrosion-sensitive rotating assemblies.

SKF specifically identifies stainless steel deep groove ball bearings as a solution for applications where corrosion can cause equipment problems or production downtime.

How to Select an SKF W 608 ZZ Replacement

When selecting a replacement, verify:

Manufacturer: SKF

Basic designation: W 608

Dimensions: 8x22x7 mm

Bearing type: Single-row deep groove ball bearing

Material: Stainless steel execution

Protection: Shields on both sides

Bore: Cylindrical

Additional suffixes: According to the original bearing

The W prefix should not be omitted if stainless steel construction is required.

FAQ - Technical Questions

What are the dimensions of SKF W 608?
The 608 dimensional series has an 8 mm bore, 22 mm outside diameter and 7 mm width.

What does W mean in SKF W 608?
W identifies an SKF metric stainless steel deep groove ball bearing.

Is SKF W 608 made from stainless steel?
Yes. SKF explicitly uses the W prefix to identify its metric stainless steel deep groove ball bearing series.

What does ZZ mean?
ZZ is commonly used commercially for metal shields on both sides. In current SKF terminology, double-sided shielded bearings are generally designated 2Z.

Does W 608 have the same dimensions as a standard 608?
Yes. The basic dimensions are 8x22x7 mm, but the W version differs in material execution.

Frequently Asked Questions from Engineers and Maintenance Technicians

Can a standard 608 replace SKF W 608?
Not automatically. If stainless steel was selected because of moisture or corrosion, a conventional bearing-steel 608 does not provide the same material execution.

Is W 608 suitable for wet environments?
The stainless steel construction provides increased corrosion resistance and is specifically relevant to wet and corrosion-sensitive applications.

Is every SKF W 608 a food-grade bearing?
No. Stainless steel construction alone does not mean that the bearing is a Food Line version. Food-grade characteristics depend on the complete SKF designation and specified lubricant, seals and materials.

What is the difference between ZZ and 2RS?
ZZ refers to metal shields, while 2RS is commonly used for seals. They provide different levels of protection and running friction.

Why is the W prefix important when ordering?
Because it identifies the stainless steel execution. A bearing ordered simply as 608 may be supplied in conventional bearing steel rather than stainless steel.