SKF 61904-2RS1 20x37x9 mm - Deep Groove Ball Bearing

SKF 61904-2RS1 20x37x9 mm - Deep Groove Ball Bearing

SKF 61904-2RS1 is a single-row deep groove ball bearing with a compact cross-section, measuring 20x37x9 mm and equipped with contact seals on both sides. This size is frequently searched for commercially as 6904 2RS SKF, while the SKF catalogue designation for the product described here is 61904-2RS1. The bearing is factory grease lubricated and designed for operation without periodic relubrication.

Technical Data - SKF 61904-2RS1

6904 2RS SKF or SKF 61904-2RS1?

This distinction is important for correct product identification.

The dimensions:

20x37x9 mm

are commonly associated in the bearing market with the designation:

6904

Customers may therefore search for this product using phrases such as:

6904 2RS SKF

SKF 6904 2RS

6904-2RS SKF

In SKF nomenclature, however, this dimensional series is designated:

61904

and the double contact-sealed variant described here is:

SKF 61904-2RS1

For precise technical identification, the recommended product name and H1 are therefore:

SKF 61904-2RS1 20x37x9 mm

The phrase 6904 2RS SKF can still be included naturally in the product content because it is an important commercial and search reference.

SKF 61904-2RS1 Dimensions

The principal dimensions are:

20x37x9 mm

where:

• d = 20 mm - bore diameter
• D = 37 mm - outside diameter
• B = 9 mm - bearing width

The bearing has a relatively small radial cross-section compared with its bore diameter.

This makes the 619 series particularly useful in bearing arrangements where radial installation space is limited.

SKF 61904-2RS1 Construction

SKF 61904-2RS1 is a single-row deep groove ball bearing.

Its construction includes:

• inner ring,
• outer ring,
• deep raceway grooves,
• one row of balls,
• cage,
• contact seal on one side,
• contact seal on the other side,
• factory grease fill.

The deep raceway geometry enables the bearing to carry primarily radial loads while also accommodating axial loads in both directions within the operating capabilities of a single-row deep groove ball bearing.

What Does 2RS1 Mean?

The SKF suffix:

2RS1

identifies a bearing with contact seals on both sides.

The seals help to:

• retain grease inside the bearing,
• reduce the ingress of contaminants,
• protect the raceways and rolling elements,
• maintain suitable lubrication conditions inside the bearing.

This is an important difference compared with an open SKF 61904 and versions equipped with other closure systems.

SKF 61904-2RS1 Load Ratings

SKF specifies:

C = 6.37 kN

Basic dynamic load rating.

C0 = 3.65 kN

Basic static load rating.

Pu = 0.156 kN

Fatigue load limit.

These values apply to the specific SKF bearing and should be used according to the manufacturer's bearing selection and calculation methodology.

SKF 61904-2RS1 Limiting Speed

SKF specifies a limiting speed of:

12000 r/min

for the double-sealed version.

Speed ratings specified for an open 61904 or other closure variants should not automatically be applied to 61904-2RS1.

The sealing arrangement influences friction and the thermal operating conditions of the bearing.

Compact 619 Series

SKF 61904-2RS1 belongs to the dimensionally compact 619 series of deep groove ball bearings.

With a bore diameter of 20 mm, the bearing has an outside diameter of only 37 mm and a width of 9 mm:

20x37x9 mm

This geometry makes the bearing suitable for designs where radial and axial installation space is restricted.

However, compact dimensions should not be considered independently of load capacity, rotational speed, fits and required bearing life.

SKF 61904-2RS1 vs SKF 61904

Both variants have the same principal dimensions:

20x37x9 mm

but they differ in their closure arrangement.

SKF 61904-2RS1 has contact seals on both sides and is supplied factory grease lubricated.

SKF 61904 is an open bearing.

Selection between the two should consider lubrication method, contamination level, speed and the requirements of the complete bearing arrangement.

SKF 61904-2RS1 vs 6904 2RS from Other Manufacturers

The dimensions 20x37x9 mm are widely identified by other manufacturers and distributors as:

6904

As a result, replacement products may carry designations such as:

6904-2RS

6904 2RS

6904-2RSR

6904 DDU

6904 LLU

Suffixes from different bearing manufacturers should not be assumed to have exactly the same technical meaning.

When selecting an alternative, verify the documentation of the specific manufacturer, including:

• seal design,
• internal clearance,
• load ratings,
• speed limits,
• cage construction,
• lubrication,
• exact bearing execution.

SKF 61904-2RS1 vs SKF 6004

Both bearings have a:

20 mm bore

but their other dimensions are significantly different.

SKF 61904-2RS1:

20x37x9 mm

SKF 6004:

20x42x12 mm

The 6004 has a larger outside diameter and greater width.

Therefore, 61904 and 6004 are not dimensionally interchangeable despite having the same bore diameter.

61904 and the 6904 Search Reference

For international B2B customers, both nomenclature systems can be important.

The exact SKF designation is:

SKF 61904-2RS1

However, customers searching by the commonly used ISO dimensional series designation may enter:

6904 2RS

or:

6904 2RS 20x37x9

Including both references helps identify the required bearing without changing the manufacturer's exact product designation.

For quotations, technical documentation and ordering of the SKF product, use:

SKF 61904-2RS1

Alternative Designations and Search References

Natural search variations include:

SKF 61904-2RS1

61904-2RS1 SKF

SKF61904-2RS1

61904 2RS1 SKF

6904 2RS SKF

SKF 6904 2RS

6904-2RS SKF

SKF 6904-2RS

SKF 61904 20x37x9

6904 SKF 20x37x9

6904 2RS 20x37x9

61904 bearing 20x37x9

6904 sealed bearing 20x37x9

For precise technical identification of the SKF product, the recommended designation is:

SKF 61904-2RS1

How to Select a Replacement

Before selecting an alternative bearing, verify:

• d = 20 mm,
• D = 37 mm,
• B = 9 mm,
• bearing type,
• single-row construction,
• seal design,
• internal clearance,
• dynamic load rating,
• static load rating,
• permissible rotational speed,
• shaft fit,
• housing fit,
• lubrication conditions,
• operating temperature,
• environmental conditions.

The generic designation:

6904 2RS

alone is not sufficient to confirm complete technical interchangeability between products from different manufacturers.

SKF 61904-2RS1 Installation

During installation:

• keep the bearing and mounting surfaces clean,
• verify shaft and housing tolerances,
• apply mounting force to the ring being press fitted,
• do not transmit mounting forces through the balls,
• protect the contact seals against damage,
• avoid direct impact on the bearing rings,
• protect the bearing against contamination.

The bearing should preferably remain in its original packaging until immediately before installation.

FAQ

What are the dimensions of SKF 61904-2RS1?

SKF 61904-2RS1 measures 20x37x9 mm. The bore diameter is 20 mm, outside diameter is 37 mm and width is 9 mm.

Is SKF 6904 2RS the same size as SKF 61904-2RS1?

The designation 6904 is commonly used in the bearing market for the 20x37x9 mm size. The SKF catalogue designation for the double contact-sealed product described here is 61904-2RS1.

What does 2RS1 mean?

SKF suffix 2RS1 identifies contact seals on both sides of the bearing.

What is the dynamic load rating of SKF 61904-2RS1?

SKF specifies a basic dynamic load rating:

C = 6.37 kN

What is the static load rating?

The basic static load rating is:

C0 = 3.65 kN

What is the fatigue load limit?

SKF specifies:

Pu = 0.156 kN

What is the limiting speed of SKF 61904-2RS1?

SKF specifies a limiting speed of:

12000 r/min

How much does SKF 61904-2RS1 weigh?

The catalogue mass is approximately:

0.038 kg

Can SKF 6004 replace SKF 61904-2RS1?

No, not as a direct dimensional replacement. SKF 61904-2RS1 measures 20x37x9 mm, while a 6004 measures 20x42x12 mm.

SKF 61904-2RS1 - Quick Answer

SKF 61904-2RS1 is a compact single-row deep groove ball bearing measuring 20x37x9 mm, with contact seals on both sides. This size is frequently searched for as 6904 2RS SKF. SKF specifies C = 6.37 kN, C0 = 3.65 kN, Pu = 0.156 kN and a limiting speed of 12000 r/min.

Available from simmering.pl, a specialist B2B supplier of bearings and technical sealing solutions for industry, manufacturers, maintenance departments and technical service companies. Shipped worldwide from stock in Poland.