SMR128ZZ EZO 8x12x3.5 mm - Miniature Stainless Steel Deep Groove Ball Bearing

SMR128ZZ EZO 8x12x3.5 mm - Miniature Stainless Steel Deep Groove Ball Bearing

EZO SMR128ZZ is a miniature stainless steel deep groove ball bearing with dimensions 8x12x3.5 mm, fitted with metal shields on both sides. The EZO SMR series identifies miniature stainless steel bearings, while ZZ indicates metal shields on both sides. Its extremely small cross-section makes the bearing suitable for compact precision mechanisms with very limited installation space.

Technical data

EZO SMR128ZZ dimensions

The basic dimensions are:

d: 8 mm
D: 12 mm
B: 3.5 mm

Complete dimensional specification:

8x12x3.5 mm

With an 8 mm bore and an outside diameter of only 12 mm, SMR128ZZ has an exceptionally small radial cross-section. This makes it suitable for compact mechanisms where very little installation space is available.

What does SMR128ZZ mean?

The complete SMR128ZZ designation identifies a specific miniature EZO bearing.

SMR - EZO miniature stainless steel bearing series.

128 - bearing size corresponding to dimensions 8x12x3.5 mm.

ZZ - metal shields on both sides of the bearing.

The complete designation should be retained when selecting or ordering the bearing, as the 8 mm bore alone does not identify the correct product.

EZO SMR128ZZ construction

SMR128ZZ is a single-row miniature deep groove ball bearing. Its basic construction consists of:

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

The deep raceway geometry is designed primarily to accommodate radial loads. Deep groove ball bearings can also accommodate axial loads within the operating limits of the specific bearing arrangement.

Stainless steel SMR series

An important feature of the EZO SMR128ZZ is its stainless steel construction.

Compared with conventional bearing steel, stainless steel provides improved corrosion resistance and can be advantageous in mechanisms exposed to moisture or other conditions where corrosion resistance is important.

Actual corrosion resistance depends on the operating environment, temperature and exposure to chemicals or other aggressive substances.

What does ZZ mean?

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

The shields help to:

• reduce the ingress of contaminants,
• protect the raceways and rolling elements,
• retain lubricant inside the bearing,
• maintain low running friction.

ZZ metal shields should not be confused with elastomer seals such as 2RS.

SMR128ZZ vs open SMR128

Both versions have the same basic dimensions:

8x12x3.5 mm

SMR128ZZ - metal shields on both sides.

SMR128 - open version without ZZ shields.

The closure type should therefore be considered when selecting a replacement bearing.

SMR128ZZ vs MR128ZZ

The complete designation is important when comparing these bearings.

SMR128ZZ identifies the stainless steel SMR series from EZO. A designation without the S prefix should not automatically be assumed to have the same material construction.

Even when dimensions are identical, material, closure type and required operating characteristics should be verified before substitution.

Ultra-compact 8x12x3.5 mm dimensions

EZO SMR128ZZ combines:

• 8 mm bore,
• 12 mm outside diameter,
• only 3.5 mm width.

The difference between the bore and outside diameter is only 4 mm, leaving an extremely small radial cross-section for the bearing rings, raceways and rolling elements.

For this reason, actual operating loads and conditions are particularly important when selecting this bearing.

Selection and interchangeability

When selecting EZO SMR128ZZ, verify:

• complete SMR128ZZ designation,
• 8 mm bore diameter,
• 12 mm outside diameter,
• 3.5 mm width,
• stainless steel construction,
• ZZ metal shields,
• required load capacity,
• operating speed,
• operating environment,
• lubrication requirements,
• shaft and housing tolerances.

Matching dimensions of 8x12x3.5 mm alone do not confirm complete technical interchangeability.

Applications

Miniature stainless steel SMR-series bearings are suitable for compact precision mechanisms where very small installation dimensions and improved corrosion resistance are required.

The suitability of SMR128ZZ for a specific application should always be evaluated according to actual loads, operating speed, environmental conditions and the design requirements of the mechanism.

Installation

Because of its extremely small cross-section, EZO SMR128ZZ should be handled carefully during installation.

When fitting the bearing onto a shaft, mounting 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 not be transmitted through the balls, and direct pressure on the ZZ metal shields should be avoided.

Alternative designations and search references

• EZO SMR128ZZ
• SMR128ZZ EZO
• SMR 128 ZZ EZO
• EZO SMR 128 ZZ
• SMR128ZZ 8x12x3.5
• EZO SMR128ZZ 8x12x3.5
• SMR 128 ZZ 8x12x3.5
• SMR128 stainless bearing
• stainless steel bearing 8x12x3.5
• miniature bearing 8x12x3.5

FAQ - EZO SMR128ZZ

What are the dimensions of EZO SMR128ZZ?

The bearing measures 8x12x3.5 mm, with an 8 mm bore, 12 mm outside diameter and 3.5 mm width.

What type of bearing is SMR128ZZ?

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

Is EZO SMR128ZZ made of stainless steel?

Yes. The EZO SMR series is a stainless steel bearing series.

What does ZZ mean?

ZZ indicates metal shields on both sides of the bearing.

Is SMR128ZZ an open bearing?

No. It has metal shields on both sides.

Why does SMR128ZZ have such a small cross-section?

With an 8 mm bore, its outside diameter is only 12 mm and its width is only 3.5 mm, allowing installation in extremely compact mechanisms.

Are SMR128ZZ and MR128ZZ the same bearing?

They should not automatically be treated as identical. SMR identifies the stainless steel EZO series, so the complete material specification and bearing execution should be checked before substitution.

Can any 8x12x3.5 mm bearing replace EZO SMR128ZZ?

Not automatically. Material construction, closure type and operating requirements must also be considered.

EZO SMR128ZZ - key information

EZO SMR128ZZ 8x12x3.5 mm is a miniature stainless steel deep groove ball bearing with metal shields on both sides. Its 8 mm bore, only 12 mm outside diameter and 3.5 mm width provide an extremely compact cross-section for precision mechanisms with limited installation space.

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