SKF 71926 ACD/P4ADGB 130x180x48 mm - Super-Precision Angular Contact Ball Bearing Set

SKF 71926 ACD/P4ADGB 130x180x48 mm - Super-Precision Angular Contact Ball Bearing Set

SKF 71926 ACD/P4ADGB is a matched set of two SKF super-precision single-row angular contact ball bearings with a 25 degree contact angle, P4A precision class and medium preload. The complete matched set measures 130x180x48 mm. Each individual 71926 ACD/P4A bearing is 24 mm wide, while DGB identifies a matched pair with preload class B.

Technical data

The load ratings, attainable speeds and mass stated above apply to an individual SKF 71926 ACD/P4A bearing. The 130x180x48 mm dimensions describe the complete two-bearing DGB matched set.

What does SKF 71926 ACD/P4ADGB mean?

The complete designation contains essential information about the bearing design and matched set.

71926 - basic designation of a 719-series angular contact ball bearing with a 130 mm bore.

ACD - SKF super-precision bearing design with a 25 degree contact angle.

P4A - SKF precision class for super-precision angular contact ball bearings.

DGB - matched set of two bearings with preload class B.

In this SKF matched-set designation, B identifies medium preload.

The DGB suffix is therefore an essential part of the product identification and should not be omitted when selecting a replacement.

Why are the dimensions 130x180x48 mm?

A single:

SKF 71926 ACD/P4A

bearing measures:

130x180x24 mm

The designation:

SKF 71926 ACD/P4ADGB

identifies a matched set consisting of two bearings.

Two 24 mm wide bearings form a set with a total nominal width of:

48 mm

The dimensions of the complete set are therefore:

130x180x48 mm

This does not mean that an individual SKF 71926 bearing is 48 mm wide.

This distinction is essential when identifying the product or comparing it with an individual 71926 ACD/P4A bearing.

Super-precision angular contact ball bearing

SKF 71926 ACD/P4ADGB belongs to the SKF family of super-precision angular contact ball bearings.

In an angular contact bearing, the raceways of the inner and outer rings are displaced relative to each other in the direction of the bearing axis.

This creates a defined contact angle between the load transmission line and the radial plane of the bearing.

An individual angular contact ball bearing can accommodate:

• radial loads

• axial loads acting in one direction

Using two correctly arranged bearings allows the bearing system to support axial loading according to the selected arrangement while providing the required stiffness and positioning characteristics.

25 degree contact angle

The ACD designation identifies a design with a:

25 degree contact angle

The contact angle is a fundamental design characteristic of an angular contact ball bearing.

It affects the relationship between radial and axial load-carrying capability as well as the stiffness characteristics of the bearing arrangement.

For this reason, 71926 ACD/P4A should not automatically be replaced with another 71926 variant having a different contact angle simply because the basic dimensions are also 130x180x24 mm.

What does P4A mean?

P4A is an SKF precision class used for super-precision bearings.

For this product, the precision class is an integral part of the complete bearing designation.

The designation:

71926 ACD/P4ADGB

should therefore not be reduced to:

71926

or even:

71926 ACD

when selecting a technically equivalent replacement.

Precision class affects the dimensional and running accuracy required from a super-precision bearing arrangement.

What does DGB mean?

DGB is one of the most important elements of this designation.

It identifies a matched set of two bearings prepared for operation together.

The final letter identifies the preload class.

For:

DGB

the letter B specifies:

medium preload

The product should therefore not be interpreted as two randomly selected individual 71926 ACD/P4A bearings.

It is a matched bearing set with a defined preload class.

Medium preload class B

Preload removes internal axial play from the bearing arrangement and influences its operating characteristics.

SKF 71926 ACD/P4ADGB uses:

preload class B - medium preload

A DGB set should not automatically be replaced with a matched set having another preload class without analysing the requirements of the spindle or bearing arrangement.

Changing preload can influence:

• system stiffness

• behaviour under load

• friction

• heat generation

• permissible operating speed

• bearing arrangement performance

• service life

The final B in DGB is therefore technically significant.

Construction of SKF 71926 ACD/P4ADGB

Each bearing in the set consists of:

• inner ring

• outer ring

• one row of balls

• angular contact raceway geometry

• cage

The bearings are of open design.

The DGB product consists of two matched single-row bearings intended to operate together.

It should not be confused with one double-row bearing.

SKF 71926 ACD/P4ADGB is a matched set of two single-row angular contact ball bearings, not one double-row bearing.

Load ratings of an individual SKF 71926 ACD/P4A

SKF specifies the following values for an individual 71926 ACD/P4A bearing:

C = 87.1 kN

Basic dynamic load rating.

C0 = 102 kN

Basic static load rating.

Pu = 3.45 kN

Fatigue load limit.

These individual-bearing values should not simply be multiplied by two to determine the load-carrying capacity of the complete DGB set.

Load distribution in a matched arrangement depends on factors including bearing arrangement, load direction, preload and operating conditions.

Attainable speeds

For an individual open SKF 71926 ACD/P4A bearing, SKF specifies attainable speeds of:

6700 r/min with grease lubrication

10000 r/min with oil-air lubrication

These are SKF catalogue values established under defined conditions.

The permissible operating speed of the complete matched set in a particular machine also depends on factors such as:

• bearing arrangement

• preload

• lubrication method

• applied load

• heat dissipation

• spindle design

• operating temperature

The catalogue speed should therefore not automatically be treated as the permissible speed of every installed DGB arrangement.

SKF 71926 ACD/P4ADGB vs 71926 ACD/P4A

The distinction is fundamental.

71926 ACD/P4A

is an individual bearing measuring:

130x180x24 mm

while:

71926 ACD/P4ADGB

is a matched set of two bearings with overall dimensions:

130x180x48 mm

and defined medium preload class B.

These designations should therefore not be treated as the same commercial product.

SKF 71926 ACD/P4ADGB vs CD design

SKF also uses the:

71926 CD/P4A

design.

Its contact angle differs from the ACD version.

The ACD design has a 25 degree contact angle.

Therefore, even when the principal dimensions of individual bearings are the same:

130x180x24 mm

the CD and ACD designs are technically different.

The complete designation should always be retained when selecting a replacement.

Matched set vs two individual bearings

Two individual bearings sharing the basic 71926 designation should not automatically be considered equivalent to:

71926 ACD/P4ADGB

In super-precision bearing arrangements, important characteristics include:

• bearing precision

• internal geometry

• contact angle

• matching

• preload

• dimensional compatibility

• bearing arrangement

If the machine specification requires DGB, the matched-set requirement and preload class must be preserved.

Alternative designations and search references

Natural identification and search references include:

• SKF 71926 ACD/P4ADGB

• 71926 ACD/P4ADGB SKF

• 71926ACD/P4ADGB

• SKF 71926ACD/P4ADGB

• 71926ACD/P4ADGB SKF

• SKF 71926 ACD P4A DGB

• 71926 ACD P4A DGB

• SKF 71926 ACD 130x180x48

• 71926 ACD/P4ADGB 130x180x48

• SKF 71926 super-precision bearing

• SKF 71926 angular contact bearing pair

• SKF 71926 matched bearing set

• SKF 71926 ACD P4A matched pair

• 71926 spindle bearing set

For technical identification, the complete manufacturer designation:

71926 ACD/P4ADGB

should be preferred.

Selection and interchangeability

Before selecting a replacement, verify:

• manufacturer

• complete designation

• 719 series

• 130 mm bore diameter

• 180 mm outside diameter

• 24 mm individual bearing width

• 48 mm complete set width

• 25 degree contact angle

• ACD design

• P4A precision class

• number of bearings in the set

• preload class B

• required bearing arrangement

• lubrication method

• rotational speed

• applied loads

• thermal operating conditions

Matching 130x180x48 mm dimensions alone do not guarantee complete interchangeability.

For super-precision spindle bearings, suffixes are essential because they define characteristics that directly influence the behaviour of the complete bearing arrangement.

Applications

SKF super-precision angular contact ball bearings are designed for bearing arrangements requiring high running accuracy, controlled stiffness and precise shaft guidance.

Typical applications for this bearing family include:

• machine tool spindles

• high-speed spindles

• machining centres

• grinding machines

• lathes

• milling machines

• precision rotating systems

These are typical applications of the super-precision angular contact bearing family.

The suitability of SKF 71926 ACD/P4ADGB for a specific spindle or machine should always be confirmed against the equipment design documentation.

Installation of SKF 71926 ACD/P4ADGB

A super-precision matched bearing set requires particularly careful installation.

During installation:

• maintain extremely clean working conditions

• protect raceways and balls against contamination

• verify shaft and housing accuracy

• observe all matched-set markings

• maintain the correct bearing orientation

• do not mix bearings from different matched sets

• use the correct mounting procedure

• never transmit mounting force through the balls

• use the specified lubrication system

Matched bearings should not be randomly exchanged with bearings from other sets.

In spindle applications, correct installation directly influences running accuracy, operating temperature and overall system performance.

FAQ

What are the dimensions of SKF 71926 ACD/P4ADGB?

The complete matched two-bearing set measures 130x180x48 mm.

What are the dimensions of one SKF 71926 ACD/P4A bearing?

An individual bearing measures 130x180x24 mm.

Is SKF 71926 ACD/P4ADGB one double-row bearing?

No. It is a matched set of two single-row super-precision angular contact ball bearings.

What does ACD mean?

ACD identifies an SKF super-precision angular contact bearing design with a 25 degree contact angle.

What does P4A mean?

P4A identifies the SKF precision class used for this super-precision bearing.

What does DGB mean?

DGB identifies a matched set of two bearings. The final B specifies medium preload.

Can two individual 71926 ACD/P4A bearings replace a DGB set?

This should not be assumed. DGB specifies a matched two-bearing set with a defined preload class. The matched-set requirements must be preserved in a super-precision application.

Are 71926 ACD/P4ADGB and 71926 CD/P4ADGB the same?

No. The bearing design and contact angle differ. ACD identifies the 25 degree contact angle design. Bearings should not be treated as identical solely because their principal dimensions match.

SKF 71926 ACD/P4ADGB - key information

SKF 71926 ACD/P4ADGB is a matched set of two super-precision single-row angular contact ball bearings with overall dimensions of 130x180x48 mm. The ACD design has a 25 degree contact angle, P4A identifies the SKF precision class, and DGB identifies a matched pair with medium preload class B.

SKF 71926 ACD/P4ADGB is available from the specialist industrial supplier simmering.pl, with stock in Poland and worldwide shipping. Assistance with identifying SKF super-precision bearings and selecting the correct bearing execution is also available.