IKO BR 243320 38.100x52.388x31.750 - Needle Roller Bearing

IKO BR 243320 38.100x52.388x31.750 mm - Inch Series Needle Roller Bearing Without Inner Ring

IKO BR 243320 is an inch-series needle roller bearing with a machined outer ring and no inner ring, manufactured by IKO, a brand of Nippon Thompson. Its catalogue dimensions are 38.100x52.388x31.750 mm, corresponding to 1 1/2 x 2 1/16 x 1 1/4 inches. The bearing is designed to accommodate high radial loads within a compact radial installation space. Its needle rollers operate directly on a suitably hardened and finished shaft surface.

Dimensional clarification: The commercial dimensions 38.100x52.300x31.700 mm are approximate. The catalogue dimensions of 38.100x52.388x31.750 mm should be used for technical identification and replacement selection.

Technical Specifications - IKO BR 243320

The bearing is intended for radial load support. Axial positioning and axial load accommodation must be provided by other suitable machine components.

Additional Catalogue Dimensions

These dimensions are important when designing the shaft, housing and adjacent components.

What Does IKO BR 243320 Mean?

BR - Inch Series Needle Roller Bearing

The BR designation identifies an inch-series needle roller bearing with a machined outer ring and without an inner ring.

Unlike drawn cup needle roller bearings, the BR series uses a machined outer ring designed to provide structural rigidity and support substantial radial loads.

243320 - Bearing Size Designation

The numerical code identifies the bearing size within the BR series.

Its corresponding dimensions are:

• Inner raceway diameter: 1 1/2 inches.

• Outside diameter: 2 1/16 inches.

• Bearing width: 1 1/4 inches.

IKO - Manufacturer Brand

IKO is a brand of Nippon Thompson, a Japanese manufacturer specialising in needle roller bearings, linear motion products and precision mechanical components.

Construction of IKO BR 243320

Machined Outer Ring

The BR 243320 features a machined outer ring rather than a thin drawn cup.

This construction provides a rigid outer raceway and is suitable for applications requiring high radial load capacity.

The outer ring must be correctly supported by the housing to maintain the intended bearing geometry and operating performance.

Needle Roller Assembly

The bearing uses long, relatively small-diameter cylindrical rollers.

Their geometry provides line contact between the rolling elements and raceways.

This allows a relatively large number of rolling elements to be accommodated within a compact radial cross-section.

The needle roller arrangement is particularly advantageous when radial installation space is limited.

Roller Cage

The cage maintains the correct spacing and guidance of the needle rollers.

It helps control roller movement during rotation and contributes to stable operation under suitable lubrication conditions.

No Inner Ring

The standard BR 243320 construction does not contain a separate inner ring.

Instead, the needle rollers operate directly on the shaft surface.

This arrangement reduces the radial space required by the bearing assembly.

However, the shaft must be suitable for use as a rolling bearing raceway.

Shaft Requirements for a Bearing Without an Inner Ring

Because the shaft forms the inner raceway, its surface condition directly affects bearing performance.

The following characteristics must be considered.

Shaft Hardness

The shaft raceway must have sufficient hardness to resist contact fatigue and permanent deformation under the needle rollers.

An ordinary untreated shaft surface may not provide the required performance.

Surface Finish

The raceway must have an appropriate surface roughness to support rolling contact and lubrication film formation.

Excessive roughness can increase wear and reduce bearing service life.

Geometrical Accuracy

Roundness, cylindricity and alignment influence load distribution across the needle rollers.

Geometrical errors may produce localised contact stresses and premature bearing damage.

Raceway Diameter

The effective shaft raceway diameter must be compatible with the bearing's specified internal geometry and required operating clearance.

Alternative Inner Ring

If the shaft cannot be hardened or finished to the required standard, a suitable separate inner ring may be considered.

However, adding an inner ring changes the required shaft diameter and installation arrangement.

The inner ring must be selected according to the bearing manufacturer's compatibility requirements.

Load Ratings - IKO BR 243320

The catalogue load ratings are:

Basic Dynamic Load Rating - 54.2 kN

The basic dynamic load rating is used in bearing fatigue life calculations.

It represents a standardised reference value rather than a universal maximum operating load.

Actual bearing life depends on the applied load, rotational speed, lubrication, contamination and shaft raceway condition.

Basic Static Load Rating - 88.2 kN

The basic static load rating is used when evaluating the risk of permanent deformation at the rolling contacts.

It is particularly relevant for stationary, slowly rotating or heavily loaded bearing arrangements.

Radial Load Capacity

Needle roller bearings are designed primarily to support radial loads.

The large effective contact length of the needle rollers contributes to high radial load capacity relative to the available radial installation space.

Axial Loads

IKO BR 243320 is not intended to independently support significant axial loads.

Where axial forces are present, the bearing arrangement must incorporate suitable axial locating elements or additional bearings.

Rotational Speed and Lubrication

The permissible rotational speed depends on the lubrication method and operating conditions.

Oil Lubrication

The catalogue limiting speed with oil lubrication is 11,000 r/min.

Adequate oil supply is essential for maintaining lubrication at the rolling contacts.

Grease Lubrication

For grease lubrication, IKO recommends using approximately 60% of the oil-lubricated limiting speed as a reference.

This corresponds to approximately 6,600 r/min.

The actual permissible speed must be evaluated according to operating temperature, loading, grease properties and lubrication conditions.

Lubrication Groove and Hole

The bearing's machined outer ring incorporates lubrication provisions that facilitate lubricant supply.

The surrounding housing and lubrication system must be designed accordingly.

Initial Lubrication

The bearing must be properly lubricated before operation.

It should not be assumed that an open needle roller bearing is supplied with a sufficient factory grease fill for immediate operation.

IKO BR 243320 vs IKO BR 243316

Both bearings belong to the same BR inch-series needle roller bearing family.

They share the same nominal inner raceway diameter and outside diameter but differ in width and load capacity.

Main Difference

BR 243320 is wider and has higher catalogue load ratings.

The additional width allows a greater effective rolling contact length.

However, the two bearings are not automatically interchangeable.

Replacement requires verification of the available axial space, shaft raceway dimensions, load requirements and housing geometry.

IKO BR 243320 vs Drawn Cup Needle Roller Bearings

The distinction between machined-ring and drawn cup needle roller bearings is important.

BR 243320 should not be described as a drawn cup bearing.

Its machined outer ring is a defining feature of the BR construction.

Bearing Selection and Interchangeability

Before ordering IKO BR 243320, verify the following requirements.

1. Exact Catalogue Dimensions

Use the catalogue dimensions:

38.100x52.388x31.750 mm

Do not rely solely on rounded commercial dimensions.

2. Shaft Raceway

Confirm that the shaft has the required hardness, surface finish and geometrical accuracy.

3. Housing Dimensions

Verify the housing bore and recommended fit for the machined outer ring.

4. Radial Loading

Evaluate the expected radial load and operating life using the appropriate bearing calculation method.

5. Axial Positioning

Provide a suitable arrangement for axial location and any axial loads present in the system.

6. Lubrication

Determine whether oil or grease lubrication is appropriate.

7. Operating Speed

Check the limiting speed against the actual lubrication method and operating conditions.

8. Environmental Protection

Because the bearing is open, the machine assembly must provide adequate protection against contaminants.

9. Replacement Compatibility

When comparing alternative brands or bearing references, verify dimensions, internal geometry, tolerances and operating specifications.

Identical nominal dimensions do not automatically guarantee full interchangeability.

Typical Applications of IKO BR 243320

Machined-ring needle roller bearings are used in mechanical assemblies requiring high radial load capacity within limited installation space.

Typical application categories include:

• Industrial gearboxes.

• Mechanical transmission systems.

• Agricultural machinery.

• Material handling equipment.

• Industrial drive mechanisms.

• Rotating shaft support assemblies.

These are general applications of this bearing type, not confirmed OEM applications of the exact IKO BR 243320 part number.

The bearing must be selected according to the specific loads, speeds, lubrication conditions and shaft design.

Installation and Maintenance

Inspect the Shaft Raceway

Before installation, verify the shaft surface condition and dimensions.

Any damage, corrosion or excessive roughness can negatively affect rolling contact performance.

Check the Housing

The housing must provide the correct fit and support for the machined outer ring.

Avoid Installation Damage

Use suitable mounting tools and procedures.

Mounting forces should be applied to the appropriate bearing ring without transmitting unnecessary forces through the needle rollers.

Provide Lubrication

Ensure that the bearing receives the specified lubricant before operation.

Where relubrication is provided, check the alignment and condition of the lubrication passages.

Check Alignment

The shaft and housing must be correctly aligned.

Excessive misalignment can create uneven loading along the needle rollers.

Monitor Operating Conditions

During service, inspect for abnormal noise, vibration, temperature increase and lubrication problems.

Contamination or inadequate lubrication can significantly reduce bearing life.

Frequently Asked Questions - IKO BR 243320

What are the exact dimensions of IKO BR 243320?

The catalogue dimensions are 38.100x52.388x31.750 mm, corresponding to 1 1/2 x 2 1/16 x 1 1/4 inches.

Is IKO BR 243320 an inch-series bearing?

Yes. BR 243320 belongs to the IKO inch-series needle roller bearing range.

Does BR 243320 have an inner ring?

No. The standard bearing is supplied without an inner ring. The needle rollers operate directly on a suitably prepared shaft raceway.

Is BR 243320 a drawn cup needle roller bearing?

No. It is a needle roller bearing with a machined outer ring.

What is the dynamic load rating of BR 243320?

The basic dynamic load rating is 54.2 kN.

What is the static load rating of BR 243320?

The basic static load rating is 88.2 kN.

What is the maximum rotational speed of BR 243320?

The catalogue limiting speed with oil lubrication is 11,000 r/min. A reference value of approximately 6,600 r/min applies when using the manufacturer's 60% guideline for grease lubrication.

Is BR 243320 sealed?

No. It is an open bearing without integrated seals.

Does BR 243320 require lubrication?

Yes. Suitable lubrication is required before operation and throughout its service life.

Can BR 243320 support axial loads?

It is primarily designed for radial loads. Significant axial loads must be accommodated by other suitable components in the bearing arrangement.

Are BR 243320 and BR 243316 interchangeable?

Not automatically. They have the same nominal inner raceway diameter and outside diameter but different widths and load ratings.

Can BR 243320 be replaced by another manufacturer's bearing?

A replacement may be possible, but dimensions, tolerances, shaft raceway requirements, load ratings and lubrication conditions must be verified.

IKO BR 243320 - Key Technical Information

IKO BR 243320 is an inch-series needle roller bearing with a machined outer ring and no inner ring. Its exact catalogue dimensions are 38.100x52.388x31.750 mm. The basic dynamic load rating is 54.2 kN, while the static load rating is 88.2 kN. The open bearing requires lubrication and a suitably prepared shaft raceway. It is designed for high radial loads in industrial mechanical assemblies.

IKO BR 243320 at simmering.pl

IKO BR 243320 can be searched by its complete manufacturer designation and inch or metric dimensions at simmering.pl.

Based in Lublin, Poland, simmering.pl supplies industrial bearings, needle roller bearings and sealing components to maintenance departments, engineering teams and international B2B customers.

For inch-series bearings, exact dimensional identification is particularly important because rounded metric dimensions may not accurately represent the original catalogue specifications.

Stock availability, dispatch dates and international shipping options can be confirmed when submitting an inquiry.