MR Miniature SeriesDeep Groove Ball Bearingscross-ref: NSK

FR4B

d 6.35 × D 15.875 × B 4.978 mm

The FR4B is a deep groove ball bearing with bore 6.35mm, outer diameter 15.875mm, and width 4.978mm rated for dynamic load 1.8 kN.

Request Quote for FR4B Search Similar

FR4B — representative product photo — Representative product

FR4B · 6.35x15.875x4.978 mm

📋 Technical Specifications

Bore (d)

6.35mm

Outer Dia. (D)

15.875mm

Width (B)

4.978mm

Dynamic Load (Cr)

1.77 kN(1770 N)

Static Load (C0r)

0.61 kN(615 N)

Reference Speed

38000rpm

Bearing type	Deep Groove Ball Bearings
Series	MR Miniature Series
Seal type	Confirm per inquiry
Material	Confirmed per inquiry — grade and certificate availability reviewed before quotation
Bore type	Confirmed per drawing
Dimension unit	millimeter (mm)

🔐 Model Code Breakdown

What each part of FR4B means.

Flange Inch

FR	FR = inch-series flange

📐 Detailed Dimensions

Basic dimensions (mm)

Bore diameter (d)	6.35
Outer diameter (D)	15.875
Width (B)	4.978

Corner radius, shoulder dimensions, fits and tolerances are confirmed against the requested suffix and application drawing before quotation.

📑 Drawings & 3D Model

📑

2D Drawing

Request drawing →

📅

3D STEP Model

Request STEP →

🔎

CAD File

Request CAD →

Drawings and 3D models are provided per inquiry. Tell us your application and we will send the appropriate file format (DXF, DWG, STEP, IGES).

⚡ Source-Data Reference Speed

Catalog reference

38,000 rpm

Lubrication method and application speed limit are confirmed per inquiry; no oil-speed value is derived from this number.

⇄ Same-size Bearings & Reference Options

The models below share the 6.35x15.875x4.978 mm boundary dimensions. Matching d/D/B alone does not prove interchangeability; verify seals, clearance, ring features, load ratings, fits, and application conditions before replacement.

Model	Relationship	Series	Seal	Action
FR4BZZ	Configuration variant	MR Miniature Series	Open	Quote →
NR4	Different outer-ring feature	Deep Groove Bearings with Snap-Ring Groove	Open	Quote →
NR4 2RZ	Different outer-ring feature	Deep Groove Bearings with Snap-Ring Groove	Rubber Seals	Quote →
NR4 ZZ	Different outer-ring feature	Deep Groove Bearings with Snap-Ring Groove	Metal Shields	Quote →
R4	Same boundary dimensions — verify fit/load	Inch R / 1600 Series	Open	Quote →
R4 2rs	Same boundary dimensions — verify fit/load	Inch R Series	Sealed	Quote →
R4B	Same boundary dimensions — verify fit/load	MR Miniature Series	Open	Quote →
R4B ZZ	Same boundary dimensions — verify fit/load	Extra Small / Miniature Deep Groove Ball Bearing Inch Series	Metal Shields	Quote →
R4BZZ	Same boundary dimensions — verify fit/load	MR Miniature Series	Metal Shields	Quote →
R4zz	Same boundary dimensions — verify fit/load	Inch R Series	Shielded	Quote →
RW4	Same boundary dimensions — verify fit/load	Inch RW Series	Open	Quote →
RW4zz	Same boundary dimensions — verify fit/load	Inch RW Series	Shielded	Quote →

⚙ Typical Applications

Electric motors

Fans and blowers

Pumps

Household appliances

Power tools

Office equipment

General machinery

Why choose NLHB?

NLHB supports both in-house manufacturing and qualified partner sourcing. We confirm the specification, supply route, inspection requirements, and available documentation before quotation.

About NLHB →

4,315

Catalog Models

15+

Years

RFQ

Specification Confirmed

❓ Frequently Asked Questions

What are the dimensions of FR4B?

The FR4B bearing has bore (d) = 6.35 mm, outer diameter (D) = 15.875 mm, and width (B) = 4.978 mm.

What is the load rating of FR4B?

Dynamic load rating (Cr) = 1.77 kN (1770 N), static load rating (C0r) = 0.61 kN.

What bearing series does FR4B belong to?

The FR4B belongs to the MR Miniature Series within the Deep Groove Ball Bearings category.

Can NLHB supply FR4B equivalents from other brands?

Depending on the model and order requirements, NLHB may manufacture in-house or source through qualified partner factories. Interchange and supply route are confirmed against your specification before quotation. All trademarks belong to their respective owners.

How do I order FR4B from NLHB?

Click "Request Quote" and send us your quantity, application, and required specifications. We review the specification, supply route, lead time, and pricing before issuing a quotation. Response time depends on specification complexity.

What materials are available for FR4B?

Material grade is confirmed per inquiry. Availability depends on the model, quantity, application, and whether the order is manufactured in-house or sourced through a qualified partner factory. Material certificates or inspection documents are confirmed before quotation when required.

Get a quote for FR4B

Send us your quantity, application and target lead time. We confirm spec, interchange and realistic delivery — no order confirmed until you approve.

Request Quote →