INA 3008 ZZ 40x68x21 Double Row Angular Contact Ball Bearing

What Is the INA 3008 ZZ Bearing?

INA 3008 ZZ, also identified as 3008-2Z / 3008-B-2Z-TVH, is a double row angular contact ball bearing with dimensions 40x68x21 mm and metal shields on both sides. Its two-row angular contact design enables it to accommodate high radial loads as well as axial loads acting in both directions. The 3008-B execution has a 25° contact angle.

Technical Specifications

Manufacturer: INA

Designation: 3008 ZZ / 3008-2Z

Catalogue execution: 3008-B-2Z-TVH

Bearing type: Angular contact ball bearing

Design: Double row

Bore diameter d: 40 mm

Outside diameter D: 68 mm

Width B: 21 mm

Dimensions: 40x68x21 mm

Contact angle: 25°

Closure: Metal shields on both sides

Radial internal clearance: CN / Normal

Cage: Polyamide

Basic dynamic load rating Cr: 25.0 kN

Basic static load rating C0r: 21.3 kN

Reference speed: 8,000 r/min

Mass: approx. 0.25 kg

What Does 3008 Mean?

The designation 3008 identifies the size within the double row angular contact ball bearing series.

Its principal dimensions are:

d: 40 mm

D: 68 mm

B: 21 mm

The complete dimensional identification is therefore 40x68x21 mm.

What Does ZZ / 2Z Mean?

ZZ is a widely used commercial designation for a bearing with metal shields on both sides. In INA/Schaeffler nomenclature, the corresponding designation is 2Z.

The shields help to:

• retain lubricant inside the bearing,
• reduce the ingress of contaminants,
• protect the balls and raceways,
• provide protection with relatively low running friction.

INA 3008-2Z is specifically listed with metal shields on both sides.

Double Row Angular Contact Design

The INA 3008-2Z is not a standard deep groove ball bearing. It is a double row angular contact ball bearing.

This design can accommodate:

• high radial loads,
• axial loads in one direction,
• axial loads in the opposite direction,
• combined radial and axial loads.

The double row arrangement provides axial location in both directions within a compact bearing width.

25° Contact Angle

The 3008-B design has a nominal 25° contact angle.

The contact angle is an important parameter because it influences the bearing's axial load carrying capability. It should therefore be considered when selecting an equivalent bearing rather than relying only on the dimensions.

Load Ratings

For the INA 3008-2Z execution, catalogue data gives:

Dynamic radial load rating Cr: 25,000 N

Static radial load rating C0r: 21,300 N

These ratings describe the bearing's load carrying capacity and are important for bearing life calculations and application verification.

CN Internal Clearance

The standard INA 3008-2Z execution is specified with CN, or Normal bearing clearance.

This parameter should be checked when replacing an existing bearing. A version with a different clearance class should not automatically be treated as technically identical.

Polyamide Cage

The 3008-B-2Z-TVH execution uses a polyamide cage.

The cage separates and guides the rolling elements. The TVH cage execution is therefore another characteristic that should be considered when identifying an exact replacement.

Shielded and Pre-Lubricated Design

The 3008-2Z version is supplied with protective shields on both sides and is factory lubricated.

This configuration protects the internal rolling contact surfaces and retains lubricant without requiring an external sealing arrangement for many standard applications.

INA 3008 ZZ vs Standard Ball Bearing

Although the product may simply be described commercially as a "ball bearing", its correct technical classification is:

Double row angular contact ball bearing

This distinction matters because the 3008 construction provides different axial load characteristics from a conventional single-row deep groove ball bearing.

Typical Applications

The INA 3008 ZZ can be used in appropriately designed:

• gearboxes,
• industrial drives,
• pumps,
• production machinery,
• mechanical transmission systems,
• agricultural machinery,
• conveyors,
• shafts requiring axial location,
• bearing arrangements exposed to combined loads.

The final bearing selection should account for load, rotational speed, temperature, shaft and housing fits, required clearance and lubrication conditions.

How to Select an INA 3008 ZZ Replacement

For correct replacement identification, verify:

Manufacturer: INA

Series: 3008

Dimensions: 40x68x21 mm

Bearing type: Double row angular contact ball bearing

Contact angle: 25°

Protection: Metal shields on both sides

Shield designation: 2Z / commercially ZZ

Internal clearance: CN

Cage: Polyamide

Matching only the 40x68x21 mm dimensions is not sufficient for exact technical identification.

FAQ - Technical Questions

What are the dimensions of INA 3008 ZZ?
The bearing has a 40 mm bore, 68 mm outside diameter and 21 mm width.

Is INA 3008 ZZ a deep groove ball bearing?
No. Its correct classification is a double row angular contact ball bearing.

What does ZZ mean?
ZZ is commonly used commercially for metal shields on both sides. INA uses the designation 2Z.

What is the contact angle of INA 3008-B-2Z-TVH?
The nominal contact angle is 25°.

What is the dynamic load rating?
The basic dynamic radial load rating is 25 kN.

What is the static load rating?
The basic static radial load rating is 21.3 kN.

Frequently Asked Questions from Engineers and Maintenance Technicians

Can INA 3008 ZZ accommodate axial loads in both directions?
Yes. Its double row angular contact design enables it to accommodate axial forces acting in both directions in addition to radial loads.

Is INA 3008 ZZ supplied lubricated?
Yes. The shielded 3008-2Z version is supplied pre-lubricated.

Does 2Z mean rubber seals?
No. 2Z identifies metal shields on both sides, not rubber contact seals.

What internal clearance does INA 3008-2Z have?
The standard catalogue execution is specified with CN, Normal clearance.

Can I select a replacement using only the 40x68x21 dimensions?
No. The double row angular contact design, 25° contact angle, 2Z shields, internal clearance and cage execution should also be checked.