R188 ZEN 6.35x12.70x3.175 Miniature Deep Groove Ball Bearing

What Is the R188 ZEN Bearing?

The R188 ZEN is a single-row miniature deep groove ball bearing with inch dimensions 6.35 x 12.70 x 3.175 mm (1/4" x 1/2" x 1/8"). Designed for compact, high-speed applications, it supports radial loads as well as moderate axial loads in both directions while maintaining low friction and smooth operation. Its miniature size makes it ideal for precision mechanisms where installation space is limited.

Bearing Design

The R188 ZEN features:

• Single-row deep groove ball bearing
• Open design
• Precision-ground raceways
• Steel balls
• Pressed steel cage
• Cylindrical bore
• Compact inch-series dimensions

The deep raceway geometry provides excellent running accuracy, low friction and reliable operation at high rotational speeds.

Technical Specification

Manufacturer: ZEN

Part Number: R188

Bearing Type: Miniature Deep Groove Ball Bearing

Design: Single Row

Inside Diameter (d): 6.35 mm (1/4")

Outside Diameter (D): 12.70 mm (1/2")

Width (B): 3.175 mm (1/8")

Seal Type: Open

Bore Type: Cylindrical

Cage: Pressed Steel

Material: Bearing Steel

Basic Dynamic Load Rating: 1080 N

Basic Static Load Rating: 438 N

How Does a Deep Groove Ball Bearing Work?

A deep groove ball bearing reduces friction between rotating and stationary components by using hardened steel balls running in precision-machined raceways.

Its primary functions include:

• Supporting radial loads
• Carrying moderate axial loads
• Reducing rotational friction
• Providing smooth and quiet operation
• Increasing equipment reliability
• Extending service life

Typical Applications

The R188 ZEN is commonly used in:

• Precision instruments
• Measuring equipment
• RC models
• Electric motors
• Small gearboxes
• Medical devices
• Robotics
• Industrial automation
• Miniature machinery
• Precision mechanical assemblies
• OEM equipment
• High-speed rotating devices

Advantages of the R188 Bearing

Key benefits include:

• Compact inch-series dimensions
• High rotational speed capability
• Low operating friction
• Smooth and quiet performance
• High dimensional accuracy
• Reliable radial and axial load support
• Suitable for precision applications
• Easy installation

Installation Recommendations

Before installation, verify:

• Shaft diameter
• Housing bore
• Bearing fit
• Lubrication requirements
• Operating speed
• Working environment

Proper mounting and lubrication help maximize bearing life and performance.

Frequently Asked Questions (FAQ)

What are the dimensions of the R188 ZEN bearing?

The bearing measures 6.35 mm bore, 12.70 mm outside diameter, and 3.175 mm width (1/4" × 1/2" × 1/8").

Is this an open bearing?

Yes. The standard R188 ZEN is supplied as an open bearing without seals or shields.

What types of loads can it support?

It is designed primarily for radial loads while also supporting moderate axial loads in both directions.

Where is the R188 bearing commonly used?

It is widely used in precision instruments, miniature motors, robotics, RC applications, automation equipment and compact mechanical assemblies.

Is this a metric or inch-series bearing?

Although the dimensions are commonly expressed in millimetres, the R188 belongs to the inch-series miniature bearing family.

What are the main advantages of the R188 design?

Its compact dimensions, low friction, high-speed capability and precision manufacturing make it ideal for miniature and high-accuracy applications.