MR128-2RS Miniature Ball Bearing (MR Bearing), Sealed, MR series

For an 8 mm shaft and a 12 mm housing bore, the MR128-2RS miniature ball bearing (MR series, sealed) is 3.5 mm wide. Modeled as simplified STEP files. Width as the shielded bearing; sealed row not listed by the sources.

How these parts are made, and what the levels mean: read the method

• Also searched as: MR128-2RS bearing
• Model id: bearings-miniature-mr128-2rs
• Standard: MR series · size MR128

Files

Part key	Simplified
bearings-miniature-mr128-2rs	STEP

Dimensions

Symbol	Name	min	nom	max	Modeled	Rule	Level
d	Bore diameter		8		8	nominal	L1
D	Outside diameter		12		12	nominal	L1
B	Width		3.5		3.5	nominal	L1
r	Chamfer dimension	0.1			0.1	single limit (min), modeled at the limit	L1

Drawing

As a PDF: CC-BRG-MINI-SZ-MR128.pdf.

The MR128-2RS miniature ball bearing beside the MR137-2RS and the MR148-2RS

The MR128-2RS is number 12, counting from the smallest, of the 13 MR series miniature ball bearings published here, from MR63-2RS to MR148-2RS.

• Bore diameter (d): 8 mm on the MR128-2RS miniature ball bearing, against 7 mm on the MR137-2RS and 8 mm on the MR148-2RS.
• Outside diameter (D): 12 mm on the MR128-2RS miniature ball bearing, against 13 mm on the MR137-2RS and 14 mm on the MR148-2RS.
• Width (B): 3.5 mm on the MR128-2RS miniature ball bearing, against 4 mm on the MR137-2RS and 4 mm on the MR148-2RS.
• Chamfer dimension (r): at least 0.1 mm on the MR128-2RS miniature ball bearing, against at least 0.15 mm on the MR137-2RS and at least 0.15 mm on the MR148-2RS.

The MR128-2RS miniature ball bearing in its other versions

• MR128 Miniature Ball Bearing (MR Bearing), MR series: width 2.5 mm.
• MR128-2Z Miniature Ball Bearing (MR Bearing), Shielded, MR series, with the same values.

Other sizes

• One size smaller: MR137-2RS Miniature Ball Bearing (MR Bearing), Sealed, MR series, 7 mm bore, 13 mm OD, 4 mm wide.
• One size larger: MR148-2RS Miniature Ball Bearing (MR Bearing), Sealed, MR series, 8 mm bore, 14 mm OD, 4 mm wide.

Documents

• CC-BRG-MINI-DS-MR128.pdf: MR128 datasheet: values with levels, sources
• CC-BRG-MINI-SZ-MR128.pdf: MR128 drawing: this size's values on the views
• parts.json: the part record of this size (the platform contract)

Sources

nmb-miniature, nsk-miniature. Full citations: the method page and this size's datasheet.

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