MR128 Miniature Ball Bearing (MR Bearing), MR series

The MR128 miniature ball bearing (MR series) has an 8 mm bore, a 12 mm outside diameter and a width of 2.5 mm. Get it as simplified STEP files.

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

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

Files

Part key	Simplified
bearings-miniature-mr128	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		2.5		2.5	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 miniature ball bearing beside the MR137 and the MR148

The MR128 is number 11, counting from the smallest, of the 12 MR series miniature ball bearings published here, from MR63 to MR148.

• Bore diameter (d): 8 mm on the MR128 miniature ball bearing, against 7 mm on the MR137 and 8 mm on the MR148.
• Outside diameter (D): 12 mm on the MR128 miniature ball bearing, against 13 mm on the MR137 and 14 mm on the MR148.
• Width (B): 2.5 mm on the MR128 miniature ball bearing, against 3 mm on the MR137 and 3.5 mm on the MR148.
• Chamfer dimension (r): at least 0.1 mm on the MR128 miniature ball bearing, against at least 0.15 mm on the MR137 and at least 0.15 mm on the MR148.

The MR128 miniature ball bearing in its other versions

• MR128-2Z Miniature Ball Bearing (MR Bearing), Shielded, MR series: width 3.5 mm.
• MR128-2RS Miniature Ball Bearing (MR Bearing), Sealed, MR series: width 3.5 mm.

Other sizes

• One size smaller: MR137 Miniature Ball Bearing (MR Bearing), MR series, 7 mm bore, 13 mm OD, 3 mm wide.
• One size larger: MR148 Miniature Ball Bearing (MR Bearing), MR series, 8 mm bore, 14 mm OD, 3.5 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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