EZO MR85ZZ 5x8x2.5 mm - Miniature Deep Groove Ball Bearing

EZO MR85ZZ 5x8x2.5 mm - Miniature Deep Groove Ball Bearing

EZO MR85ZZ is a miniature single-row deep groove ball bearing with dimensions 5x8x2.5 mm, manufactured by Kitanihon Seiki under the EZO brand. It has a 5 mm bore diameter, 8 mm outside diameter and 2.5 mm width. The ZZ version features metal shields on both sides. The basic dynamic load rating Cr is 218 N, while the basic static load rating C0 is 91 N.

Technical data - EZO MR85ZZ

What does EZO MR85ZZ mean?

The designation MR85ZZ identifies a specific EZO miniature deep groove ball bearing.

MR85 identifies the bearing series and size.

ZZ indicates metal shields fitted on both sides of the bearing.

The complete product identification is:

EZO MR85ZZ - 5x8x2.5 mm - miniature deep groove ball bearing with metal shields on both sides.

EZO MR85ZZ dimensions

The manufacturer's technical data specifies:

• d - bore diameter: 5 mm

• D - outside diameter: 8 mm

• B - width: 2.5 mm

Complete dimensions:

5x8x2.5 mm

The corresponding nominal inch dimensions are approximately:

0.1969x0.315x0.0984 in

The combination of a 5 mm bore and an outside diameter of only 8 mm makes MR85ZZ an extremely compact miniature bearing.

Load ratings of EZO MR85ZZ

According to EZO technical data:

Cr - basic dynamic load rating: 218 N

C0 - basic static load rating: 91 N

These ratings apply specifically to the MR85ZZ version.

Load ratings from other bearings with an 8 mm outside diameter or from different MR85 variants should not be transferred to this product.

Limiting speed

The manufacturer specifies the following limiting speeds:

• grease lubrication: 63,000 min-1

• oil lubrication: 75,000 min-1

The lubrication method therefore affects the specified limiting speed of the bearing.

EZO MR85ZZ construction

MR85ZZ is a miniature single-row deep groove ball bearing.

Its construction consists of:

• inner ring

• outer ring

• balls

• cage

• two metal shields

The manufacturer specifies:

Ball diameter: 0.800 mm

Number of balls: 9

The deep groove raceway geometry is designed primarily to accommodate radial loads while also allowing axial loads in both directions within the operating limits of this bearing type.

What does ZZ mean in MR85ZZ?

The suffix ZZ indicates metal shields on both sides of the bearing.

The shields help to:

• reduce the ingress of contaminants

• retain lubricant inside the bearing

• provide protection with low additional friction

Metal shields should not be confused with contacting elastomer seals. These are different protection systems and can affect friction, speed capability and protection against contamination.

EZO MR85ZZ vs MR85

EZO also catalogues an open version:

MR85 - 5x8x2 mm

while the shielded version is:

MR85ZZ - 5x8x2.5 mm

The two versions therefore differ by more than the presence of shields.

The open MR85 has a width of 2 mm, while MR85ZZ has a width of 2.5 mm.

The manufacturer also specifies different load ratings for these variants.

MR85

• Cr: 309 N

• C0: 121 N

MR85ZZ

• Cr: 218 N

• C0: 91 N

MR85 and MR85ZZ should therefore be treated as separate technical variants.

EZO MR85ZZ vs SMR85ZZ

The EZO catalogue also includes:

SMR85ZZ - 5x8x2.5 mm

MR85ZZ and SMR85ZZ have the same basic dimensions but are separate manufacturer references.

For MR85ZZ, the specified dynamic load rating Cr is 218 N, while the SMR85ZZ version has a different specified load rating.

The designations MR85ZZ and SMR85ZZ should therefore not be treated as identical.

Alternative designations and search references

The product may also be searched as:

• EZO MR85ZZ

• MR85ZZ EZO

• EZO MR 85 ZZ

• MR 85 ZZ EZO

• MR85 ZZ

• MR 85 ZZ

• MR85ZZ 5x8x2.5

• EZO MR85ZZ 5x8x2.5

• MR85ZZ bearing

• EZO 5x8x2.5 bearing

• 5x8x2.5 ball bearing

• miniature bearing 5x8x2.5

• miniature deep groove ball bearing 5x8x2.5

For precise identification, the original manufacturer designation should be retained:

MR85ZZ

Selecting EZO MR85ZZ

Before ordering, verify:

• complete designation MR85ZZ

• 5 mm bore diameter

• 8 mm outside diameter

• 2.5 mm width

• ZZ shield configuration

• required load capacity

• operating speed

• lubrication conditions

• operating environment

• requirements of the specific mechanism

Particular attention should be paid to the width because the open MR85 has a width of 2 mm, while MR85ZZ has a width of 2.5 mm.

Installation

Due to its very small dimensions, MR85ZZ requires careful handling and precise installation.

The bearing, shaft and housing should be clean before assembly.

When press-fitting the bearing onto a shaft, installation force should be applied to the inner ring. When fitting the bearing into a housing, force should be applied to the outer ring.

Installation force should never be transmitted through the balls, and the bearing should not be struck directly.

Care should also be taken to avoid deforming the thin metal shields.

FAQ

What are the dimensions of EZO MR85ZZ?

EZO MR85ZZ has dimensions of 5x8x2.5 mm: 5 mm bore diameter, 8 mm outside diameter and 2.5 mm width.

What type of bearing is EZO MR85ZZ?

It is a miniature single-row deep groove ball bearing.

What does ZZ mean in MR85ZZ?

ZZ indicates metal shields on both sides of the bearing.

What is the dynamic load rating of EZO MR85ZZ?

The basic dynamic load rating Cr is 218 N.

What is the static load rating of EZO MR85ZZ?

The basic static load rating C0 is 91 N.

What is the limiting speed of EZO MR85ZZ?

The manufacturer specifies 63,000 min-1 with grease lubrication and 75,000 min-1 with oil lubrication.

How many balls does EZO MR85ZZ contain?

The manufacturer specifies 9 balls with a diameter of 0.800 mm.

Are MR85 and MR85ZZ the same size?

No. MR85 has dimensions of 5x8x2 mm, while MR85ZZ has dimensions of 5x8x2.5 mm.

Are MR85ZZ and SMR85ZZ the same bearing?

No. They are separate EZO catalogue references. Although their basic dimensions are the same, their technical specifications differ, so the complete designation should always be verified.

EZO MR85ZZ - key information

EZO MR85ZZ is a miniature single-row deep groove ball bearing with dimensions 5x8x2.5 mm and metal shields on both sides. The manufacturer specifies a basic dynamic load rating of 218 N, a basic static load rating of 91 N, and limiting speeds of 63,000 min-1 with grease lubrication and 75,000 min-1 with oil lubrication.

Available from simmering.pl, a specialist supplier of bearings, seals and industrial components. Stock in Poland with worldwide shipping.