SR166ZZ EZO 4.762x9.525x3.175 mm - Stainless Steel Deep Groove Ball Bearing

SR166ZZ EZO 4.762x9.525x3.175 mm - Stainless Steel Deep Groove Ball Bearing

EZO SR166ZZ is a miniature inch-series stainless steel deep groove ball bearing with dimensions 4.762x9.525x3.175 mm. The ZZ version features metal shields on both sides. Its dimensions correspond to the nominal inch size 3/16x3/8x1/8 inch. The compact stainless steel construction and non-contact metal shields make it suitable for precision mechanisms requiring small installation dimensions and low-friction operation.

Technical data

EZO SR166ZZ dimensions

The SR166ZZ bearing has the following dimensions:

d: 4.762 mm
D: 9.525 mm
B: 3.175 mm

In inch dimensions:

3/16x3/8x1/8 inch

SR166ZZ belongs to an inch-dimensional bearing series. This is particularly important when selecting a replacement because the dimensions 4.762 mm and 9.525 mm originate directly from imperial dimensions.

The 4.762 mm bore should not be rounded to 5 mm, and the 9.525 mm outside diameter should not be treated as 10 mm.

What does SR166ZZ mean?

The complete designation SR166ZZ identifies a specific EZO miniature bearing configuration.

S - stainless steel construction.

R166 - bearing size from the miniature inch series.

ZZ - metal shields on both sides of the bearing.

The complete SR166ZZ designation should be retained when ordering a replacement because bearings with similar dimensions may differ in material, closure type and construction.

EZO SR166ZZ construction

SR166ZZ is a single-row deep groove ball bearing.

Its basic construction consists of:

• inner ring,
• outer ring,
• balls,
• cage,
• two metal shields.

Deep groove ball bearing geometry is designed primarily to accommodate radial loads while also allowing axial loads within the operating capabilities of this bearing type.

Stainless steel construction

EZO SR166ZZ is manufactured as a stainless steel bearing.

Stainless steel construction is important in mechanisms where improved corrosion resistance is required compared with conventional bearing steel.

However, stainless steel does not mean complete resistance to every corrosive environment. Actual suitability depends on operating conditions, moisture, chemicals, temperature and the lubricant used.

What does ZZ mean?

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

These shields help:

• reduce the ingress of contaminants,
• retain lubricant inside the bearing,
• protect the rolling elements without using contact elastomer seals.

Metal shields are non-contact components and therefore generally produce less additional friction than contact seals, an important characteristic in miniature bearing applications.

SR166ZZ and inch dimensions

The dimensions 4.762x9.525x3.175 mm may appear unusual when compared with standard metric bearings.

They correspond directly to:

3/16 inch = 4.7625 mm
3/8 inch = 9.525 mm
1/8 inch = 3.175 mm

For this reason, the SR166ZZ should be treated as an inch-series miniature bearing, not as an approximately equivalent metric bearing.

Replacing it with the nearest metric dimensions may result in incorrect shaft or housing fits.

SR166ZZ vs R166ZZ

The two versions can share the same basic dimensions but differ in material specification.

SR166ZZ - stainless steel version.

R166ZZ - standard R166 version.

If the original component is an SR166ZZ, the required material should be considered in addition to the dimensions when selecting a replacement.

ZZ vs 2RS

These configurations differ primarily in the way the bearing interior is protected.

ZZ - metal shields on both sides, non-contact construction.

2RS - elastomer seals on both sides, typically contact-type construction.

ZZ is particularly useful where low running friction is important. A 2RS version may provide greater protection against certain contaminants but has different friction characteristics.

A ZZ bearing should therefore not automatically be replaced with a 2RS version without checking the operating requirements.

Selection and interchangeability

When selecting an EZO SR166ZZ, verify:

• complete SR166ZZ designation,
• 4.762 mm bore diameter,
• 9.525 mm outside diameter,
• 3.175 mm width,
• 3/16x3/8x1/8 inch dimensions,
• stainless steel construction,
• ZZ metal shields,
• required load capacity,
• operating speed,
• environmental conditions,
• lubrication requirements,
• shaft and housing fits.

Similar external dimensions alone do not confirm full interchangeability.

Applications

Miniature EZO inch-series bearings are suitable for compact precision mechanisms where small installation dimensions and accurate rotary motion are required.

The suitability of SR166ZZ for a specific application should be determined from the equipment documentation, operating conditions and bearing arrangement requirements.

Installation

Due to the small dimensions of the SR166ZZ, correct installation is particularly important.

When mounting the bearing onto a shaft, installation force should be applied to the inner ring. When pressing the bearing into a housing, force should be applied to the outer ring.

Mounting force should never be transmitted through the balls, as this can damage the raceways and adversely affect bearing performance.

Alternative designations and search references

This bearing may also be searched for as:

• EZO SR166ZZ
• SR166ZZ EZO
• SR 166 ZZ EZO
• SR166 ZZ EZO
• SR166ZZ 4.762x9.525x3.175
• SR166ZZ 3/16x3/8x1/8
• EZO SR166ZZ 3/16x3/8x1/8
• SR166ZZ stainless bearing
• EZO stainless steel bearing SR166ZZ
• 4.762x9.525x3.175 bearing
• 3/16x3/8x1/8 bearing

FAQ - EZO SR166ZZ

What are the dimensions of EZO SR166ZZ?

The bearing measures 4.762x9.525x3.175 mm, corresponding nominally to 3/16x3/8x1/8 inch.

Is SR166ZZ a stainless steel bearing?

Yes. It is a miniature EZO deep groove ball bearing in stainless steel construction.

Is SR166ZZ a metric bearing?

No. It belongs to an inch-dimensional miniature bearing series.

Does SR166ZZ have a 5 mm bore?

No. The nominal bore is 3/16 inch, approximately 4.762 mm.

What does ZZ mean?

ZZ indicates metal shields on both sides of the bearing.

What is the outside diameter of SR166ZZ?

The outside diameter is 9.525 mm, corresponding to 3/8 inch.

Are SR166ZZ and R166ZZ identical?

They should not be considered identical. SR166ZZ is the stainless steel version, so the material specification should be considered when selecting a replacement.

Can SR166ZZ be replaced with a 2RS version?

Not automatically. ZZ and 2RS use different closure systems and have different sealing and friction characteristics.

EZO SR166ZZ - key information

EZO SR166ZZ 4.762x9.525x3.175 mm is a miniature inch-series stainless steel deep groove ball bearing. It corresponds to 3/16x3/8x1/8 inch dimensions and features metal ZZ shields on both sides. When selecting a replacement, the inch dimensions, stainless steel construction and closure type should all be verified.

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