HK4520 NTN 45x52x20 Drawn Cup Needle Roller Bearing

HK4520 NTN is an open drawn cup needle roller bearing with dimensions 45x52x20 mm. For this bearing design, Fw = 45 mm is the diameter under the rollers, D = 52 mm is the outside diameter, and C = 20 mm is the bearing width. HK4520 has a thin-walled drawn outer cup and no integral inner ring.

HK4520 NTN - Product Characteristics

The exact NTN designation is HK4520. NTN classifies this bearing as a drawn cup needle roller bearing, open end.

Its technical identification is:

HK4520 -> NTN -> drawn cup needle roller bearing -> open end -> Fw 45 mm -> D 52 mm -> C 20 mm

A key feature of this construction is its small radial cross-section. The bearing combines a 45 mm diameter under the rollers with an outside diameter of only 52 mm.

Dimensions

The verified dimensions of HK4520 NTN are:

Fw - Diameter Under Rollers: 45 mm
D - Outside Diameter: 52 mm
C - Width: 20 mm
Commercial Dimensions: 45x52x20 mm
Weight: 0.058 kg

For technical descriptions of HK4520, the first dimension should not automatically be labelled as a conventional bearing bore d. NTN specifies this dimension as Fw = 45 mm, because the bearing does not contain an integral inner ring.

Drawn Cup Needle Roller Construction

HK4520 uses needle rollers, which are cylindrical rolling elements with a relatively small diameter compared with their length.

The rollers operate inside a thin-walled drawn outer cup. This construction provides a high radial load-carrying capacity relative to the radial installation space required.

The bearing is open at both ends. This distinguishes HK4520 from a BK-series drawn cup needle roller bearing, where the outer cup is closed at one end.

No Integral Inner Ring

HK4520 does not have an integral inner ring.

In a standard installation, the needle rollers can operate directly on a suitably prepared shaft surface that serves as the inner raceway.

This is an important distinction when interpreting the 45x52x20 mm dimensions. The 45 mm value represents Fw, the diameter under the rollers, rather than the bore of a conventional inner ring.

Where the shaft cannot provide a suitable raceway, NTN identifies IR40X45X20.5 as a separate inner ring for this bearing.

Radial Load Carrying Capacity

HK4520 is primarily designed to accommodate radial loads.

The verified NTN ratings are:

Basic Dynamic Load Rating Cr: 27.6 kN
Basic Static Load Rating C0r: 59 kN

These are standardized bearing ratings and should not be interpreted as the maximum permissible load of the complete machine assembly.

Actual bearing selection must also consider load conditions, required bearing life, shaft and housing fits, lubrication, operating speed and the quality of the raceway surfaces.

Speed Ratings

For HK4520 NTN, catalog data specify different limiting speeds depending on lubrication:

Grease Lubrication: 3,700 rpm
Oil Lubrication: 5,500 rpm

The lubrication method is therefore an important factor when evaluating the permissible operating speed of this bearing.

Open-End Design

The HK series identifies a drawn cup needle roller bearing with an open-end construction.

HK4520 should therefore be distinguished from variants with different structural features. For example:

HK4520 - open-end drawn cup needle roller bearing
BK4520 - closed-end drawn cup needle roller bearing

These variants should not be treated as identical solely because their principal dimensions are related.

Lubrication Hole

The standard HK4520 NTN is specified without a lubrication hole in the outer ring.

This feature is relevant when comparing it with other variants of the same dimensional family. For example, an HK4520D designation identifies a different configuration and should not be merged with the standard HK4520 product specification.

Operating Temperature

Current NTN-SNR European product data specify an operating temperature range of:

Minimum Temperature: -20°C
Maximum Temperature: +120°C

Other regional NTN documentation may specify a different lower temperature limit. For a European product listing, the current NTN-SNR European specification should therefore be used unless documentation for the exact supplied batch states otherwise.

Meaning of the HK4520 Designation

HK identifies an open-end drawn cup needle roller bearing series.

For this reference:

45 corresponds to the nominal Fw = 45 mm diameter under the rollers.

20 corresponds to the C = 20 mm bearing width.

The exact HK4520 designation should be retained when ordering or comparing the bearing because related HK, BK and modified variants can differ in construction.

Selection and Interchangeability

When selecting an equivalent for HK4520 NTN, verify:

• Fw = 45 mm
• D = 52 mm
• C = 20 mm
• drawn cup needle roller construction
• open-end configuration
• absence of an integral inner ring
• dynamic and static load ratings
• permissible operating speed
• lubrication method
• shaft raceway requirements

Matching only the commercial 45x52x20 mm dimensions does not establish full technical interchangeability.

Technical Specification

Manufacturer: NTN
Designation: HK4520
Bearing Type: Drawn cup needle roller bearing
Design: Open end
Commercial Dimensions: 45x52x20 mm
Fw - Diameter Under Rollers: 45 mm
D - Outside Diameter: 52 mm
C - Width: 20 mm
Integral Inner Ring: No
Separate Inner Ring: IR40X45X20.5
Lubrication Hole: No
Basic Dynamic Load Rating Cr: 27.6 kN
Basic Static Load Rating C0r: 59 kN
Limiting Speed with Grease: 3,700 rpm
Limiting Speed with Oil: 5,500 rpm
Operating Temperature: -20°C to +120°C according to current European NTN-SNR data
Weight: 0.058 kg

FAQ

What are the dimensions of HK4520 NTN?

HK4520 has commercial dimensions of 45x52x20 mm, corresponding to Fw = 45 mm, D = 52 mm and C = 20 mm.

What type of bearing is NTN HK4520?

It is an open-end drawn cup needle roller bearing with a thin-walled drawn outer cup.

Does HK4520 have an inner ring?

No. HK4520 does not have an integral inner ring. The needle rollers normally operate against a suitably prepared shaft raceway.

Is 45 mm the bore diameter of HK4520?

More precisely, NTN specifies Fw = 45 mm, the diameter under the needle rollers. It should not be described as a conventional bore diameter d because HK4520 has no integral inner ring.

Which inner ring can be used with HK4520 NTN?

NTN identifies IR40X45X20.5 as a separate inner ring associated with HK4520 where an inner ring is required.

What are the load ratings of NTN HK4520?

The basic dynamic radial load rating Cr is 27.6 kN, while the basic static radial load rating C0r is 59 kN.

What is the limiting speed of HK4520?

The catalog values are 3,700 rpm with grease lubrication and 5,500 rpm with oil lubrication.

Are HK4520 and BK4520 the same bearing?

No. HK4520 is open at both ends, whereas BK4520 is a closed-end drawn cup needle roller bearing. The construction must be checked when selecting a replacement.

AI Overview

HK4520 NTN is an open-end drawn cup needle roller bearing with dimensions Fw 45 mm, D 52 mm and C 20 mm. It has a thin-walled drawn outer cup and no integral inner ring. NTN specifies a dynamic radial load rating of 27.6 kN and a static radial load rating of 59 kN.

SHORT DESCRIPTION

HK4520 NTN is an open drawn cup needle roller bearing with commercial dimensions 45x52x20 mm: Fw = 45 mm, D = 52 mm and C = 20 mm. It has no integral inner ring, so the 45 mm dimension is correctly identified as the diameter under the rollers rather than a conventional bore d. NTN identifies IR40X45X20.5 as a separate inner ring. Dynamic radial load rating Cr: 27.6 kN; static C0r: 59 kN. Limiting speed: 3,700 rpm with grease and 5,500 rpm with oil. Weight: 0.058 kg.