SKF 608 ZZ C4 8x22x7 mm Deep-Groove Ball Bearing

Technical Specifications - SKF 608 ZZ C4

Dynamic load rating C, static load rating C0, fatigue load limit Pu, limiting speed, mass, cage material and the specific lubricant must be verified against the exact SKF 608-2Z/C4 catalog variant.

These specifications should not be transferred from 608-2Z, 608-2Z/C3 or other related versions.

What Does SKF 608 ZZ C4 Mean?

SKF - Manufacturer

SKF is an international manufacturer of rolling bearings and related engineering solutions for rotating equipment.

The 608 bearing belongs to the family of single row deep groove ball bearings, a design primarily intended for radial loads while also accommodating axial loads in both directions within its operating limits.

608 - Basic Bearing Designation

The designation 608 identifies a specific deep groove ball bearing size and construction.

Its principal dimensions are:

• Inside diameter (d): 8 mm.

• Outside diameter (D): 22 mm.

• Width (B): 7 mm.

The bearing contains one row of balls positioned between the inner and outer ring raceways.

The deep groove raceway geometry enables the bearing to support radial loads and certain axial loads in both directions.

ZZ - Metal Shields on Both Sides

ZZ is a widely used designation indicating two metal shields, one on each side of the bearing.

SKF uses the designation 2Z for this configuration.

The shields help limit the entry of larger contaminants into the bearing and reduce lubricant escape.

Unlike contact seals, non-contact metal shields do not create the same type of sealing friction against the inner ring.

This construction is suitable for applications where relatively low shield-related friction is important.

However, metal shields do not provide the same protection against moisture and fine contamination as appropriately selected contact seals.

C4 - Increased Radial Internal Clearance

C4 identifies radial internal clearance greater than C3.

SKF uses several radial internal clearance classes:

Radial internal clearance describes the total possible radial displacement of one bearing ring relative to the other before mounting, measured under specified conditions.

The actual operating clearance may change after installation due to interference fits, temperature differences and applied loads.

C4 clearance may be required where mounting conditions or thermal effects are expected to reduce the initial clearance significantly.

C4 does not automatically mean that the bearing is suitable for higher rotational speeds than C3 or CN versions.

The correct clearance class must be determined from the requirements of the application.

Construction and Operating Principle

Inner and Outer Rings

The bearing consists of an inner ring with an 8 mm bore and an outer ring with a 22 mm outside diameter.

Both rings contain precisely formed raceways that guide the rolling elements.

Correct shaft and housing fits are essential for bearing performance and the resulting operating clearance.

Rolling Elements

A single row of balls transmits loads between the inner and outer rings.

The deep groove ball bearing design is primarily suited to radial loads but can also accommodate axial loads in both directions.

The permissible load levels depend on the exact bearing specification and operating conditions.

Bearing Cage

The cage separates the balls and maintains their relative spacing during rotation.

The exact cage material for SKF 608-2Z/C4 should be confirmed from the manufacturer's documentation.

The designation 608 ZZ C4 alone does not uniquely specify the cage material.

Double Metal Shields

Two metal shields protect the internal bearing space from external contamination.

They also help retain lubricant inside the bearing.

The non-contact shield design differs from rubber contact seals such as SKF 2RSH.

Shielded bearings should not be treated as equivalent to fully contact-sealed bearings in contaminated or wet environments.

C4 Clearance Under Operating Conditions

SKF 608-2Z/C4 has greater initial radial internal clearance than corresponding CN and C3 variants.

During installation, tight fits may reduce the available internal clearance.

Temperature differences between the inner and outer rings can also influence the effective operating clearance.

In applications where these effects are significant, C4 may be specified to achieve the required clearance during operation.

However, excessive operating clearance may increase vibration, noise and shaft displacement.

For this reason, C4 should be selected according to the mechanical and thermal requirements of the equipment.

Alternative Designations and Reference Numbers

The bearing may appear under the following notation variants:

• SKF 608 ZZ C4

• 608 ZZ C4 SKF

• SKF 608-2Z/C4

• 608-2Z/C4 SKF

• SKF 608 2Z C4

• SKF 608 ZZ C4 8x22x7

The designation 608-2Z/C4 follows SKF nomenclature for a bearing with two metal shields and C4 radial internal clearance.

When ordering, the complete manufacturer designation should be checked against the bearing packaging or supply documentation.

No unverified OEM references or cross-manufacturer interchange numbers are assigned to this product.

SKF 608 ZZ C4 vs Other 608 Bearing Variants

SKF 608-2Z/C4 vs SKF 608-2Z/C3

Both variants have the same dimensions of 8x22x7 mm and two metal shields.

The principal difference is radial internal clearance.

SKF 608-2Z/C4 has greater clearance than SKF 608-2Z/C3.

Replacing C4 with C3 without checking the application may result in insufficient operating clearance, particularly where interference fits or temperature differences are significant.

SKF 608-2Z/C4 vs SKF 608-2Z

SKF 608-2Z without an additional clearance suffix generally has normal internal clearance.

SKF 608-2Z/C4 has increased radial internal clearance greater than C3.

This difference affects bearing selection for specific mounting fits, temperatures and operating loads.

These variants should not be considered automatically interchangeable.

SKF 608-2Z/C4 vs SKF 608-2RSH

SKF 608-2Z/C4 uses two non-contact metal shields.

SKF 608-2RSH uses two contact seals.

Contact seals provide a different level of protection against contaminants but introduce additional sealing friction.

Furthermore, SKF 608-2RSH without a clearance suffix does not automatically have C4 clearance.

The two variants therefore differ in sealing construction and potentially in internal clearance.

Selection and Interchangeability

Before purchasing SKF 608 ZZ C4, verify the following:

1. Complete SKF designation 608-2Z/C4.

2. Shaft diameter of 8 mm.

3. Housing bore diameter of 22 mm.

4. Bearing width of 7 mm.

5. Two metal shields.

6. Required C4 radial internal clearance.

7. Inner and outer ring mounting fits.

8. Operating temperature and temperature differences between bearing rings.

9. Radial and axial loads.

10. Rotational speed.

11. Lubrication requirements.

12. Environmental contamination conditions.

Bearings with identical dimensions of 8x22x7 mm are not necessarily interchangeable.

Open, shielded and contact-sealed versions may differ in friction, contamination protection and lubrication requirements.

Differences between normal, C3 and C4 internal clearance are equally important.

The correct bearing should be selected using the complete designation and the operating requirements of the equipment.

Applications of SKF 608 ZZ C4

Single row deep groove ball bearings in the 608 size are used in compact rotating mechanisms where limited installation space is available.

Typical application categories for bearings of this size include:

• Small rotating assemblies.

• Guide rollers.

• Compact mechanical mechanisms.

• Small shaft support arrangements.

• Selected low-load rotating components.

These are general applications of 608-size deep groove ball bearings, not confirmed equipment-specific applications of SKF 608-2Z/C4.

The C4 version should be selected only when the application requires increased radial internal clearance.

It should not automatically be chosen for rollers, wheels, electric motors or other rotating equipment solely because the installation dimensions are 8x22x7 mm.

Installation and Operating Recommendations

Preparation Before Installation

Before installation, inspect the shaft and housing bore.

Both mounting surfaces should be clean and free from burrs, corrosion and mechanical damage.

Verify the required fits because interference can reduce the bearing's internal clearance after mounting.

Correct Application of Mounting Force

When mounting the bearing onto a shaft with an interference fit, apply installation force to the inner ring.

When installing the bearing into a housing with an interference fit, apply force to the outer ring.

Do not transmit mounting forces through the balls and raceways.

Incorrect force application may damage the rolling elements and raceway surfaces.

Lubrication and Shields

SKF deep groove ball bearings with two metal shields are generally supplied as factory-lubricated units.

The exact lubricant type and grease fill for the SKF 608-2Z/C4 variant should be verified using manufacturer documentation.

Do not remove the shields or add lubricant without a technically justified procedure.

Storage

Store the bearing in its original packaging in a clean, dry environment.

Protect it from moisture, contamination, vibration and mechanical damage.

FAQ - SKF 608 ZZ C4

1. What are the dimensions of SKF 608 ZZ C4?

The bearing has an inside diameter of 8 mm, an outside diameter of 22 mm and a width of 7 mm.

2. What does ZZ mean in SKF 608 ZZ C4?

ZZ indicates two metal shields, one on each side of the bearing. SKF uses the designation 2Z for this shield arrangement.

3. What does C4 mean in SKF 608?

C4 specifies radial internal clearance greater than C3. This clearance class is intended for applications requiring increased initial clearance.

4. Are SKF 608 ZZ C4 and SKF 608-2Z/C4 the same designation?

Technically, ZZ and 2Z both describe two metal shields, while C4 identifies the same clearance class. SKF 608-2Z/C4 is the designation consistent with SKF nomenclature. The exact product designation should be verified against the packaging.

5. Can SKF 608-2Z/C4 be replaced with SKF 608-2Z/C3?

Not without checking the operating conditions. C3 has less internal clearance than C4. Substitution may affect operating clearance, temperature and bearing service life.

6. Is SKF 608 ZZ C4 factory lubricated?

SKF bearings with two metal shields are generally supplied with factory lubrication. The specific grease used in the exact 608-2Z/C4 variant should be confirmed from SKF documentation.

7. Is SKF 608 ZZ C4 suitable for high rotational speeds?

Deep groove ball bearings with non-contact shields can be suitable for relatively high rotational speeds. However, the permissible speed of the specific bearing depends on its catalog specifications, lubrication, loading and operating temperature.

8. Are all 608 bearings measuring 8x22x7 mm interchangeable with SKF 608 ZZ C4?

No. The shield or seal design, radial internal clearance, lubrication and operating requirements must also match. Identical dimensions alone do not guarantee interchangeability.

SKF 608 ZZ C4 8x22x7 mm - Key Technical Information

SKF 608 ZZ C4 is a single row deep groove ball bearing measuring 8x22x7 mm. It features two non-contact metal shields and C4 radial internal clearance, greater than C3. The corresponding SKF designation is 608-2Z/C4. Correct selection requires consideration of mounting fits, operating temperatures and the required internal clearance during operation.

The SKF 608 ZZ C4 8x22x7 mm bearing is offered by simmering.pl, a specialist supplier of rolling bearings, industrial sealing components and radial shaft seals.

TG Ersatzteile Polska Sp. z o.o. operates a warehouse in Lublin, Poland, supplying industrial maintenance departments, engineering companies, workshops and international B2B customers.

Products are shipped from stock in Poland, with shipping options available throughout Europe and worldwide.