MR Miniature Bearings Size Chart: MR63, MR85, MR105, MR128

Same 5 mm bore, six outside diameters

At a 5 mm bore the MR series gives four thin envelopes. The 69x and 62x sizes with the same bore are larger. The cross-section height is (D − d) / 2.

Model	Series	d	D	B	Section height
MR85	MR	5	8	2.5	1.5
MR95	MR	5	9	3	2
MR105	MR	5	10	4	2.5
MR115	MR	5	11	4	3
695	69x	5	13	4	4
625	62x	5	16	5	5.5

How MR bearing numbers are built

Number or suffix	Meaning	Example
MR + D + d	MR, then the outside diameter, then the bore, in millimetres.	MR105 = 5 × 10 × 4
X	The bore is not a whole millimetre.	MR41X = 1.2 × 4 × 1.8
MR5-2.5	Decimal bores are written after a hyphen.	MR5-2.5 = 2.5 × 5 × 1.5
B	A width variant of the same bore and OD. Check B in the table.	MR52 = 2 × 5 × 2.5, MR52B = 2 × 5 × 2
ZZ / 2RS / 2RZ	Metal shields / contact rubber seals / non-contact rubber seals	MR105ZZ, MR105 2RS

MR miniature bearing size charts

Each row is one size. Open, shielded and sealed versions that share the size are listed together and link to their model pages, where load ratings and drawings are given. Dimensions are in millimetres.

Bore 1 to 2.5 mm Bore 3 to 4 mm Bore 5 to 8 mm

Bore 1 to 2.5 mm

d	D	B	Models
1	3	1.5	MR31
1.2	4	1.8	MR41x
1.2	4	2.5	MR41X ZZ
2	4	1.2	MR42
2	4	2	MR42 ZZ
2	5	2	MR52B
2	5	2.5	MR52 MR52 2rs MR52 ZZ MR52BZZ
2	6	2.5	MR62 MR62 2rs MR62 ZZ
2	7	2.5	MR72
2	7	3	MR72 2rs MR72 ZZ
2.3	9	3	MR9-2.3 MR9-2.3 ZZ
2.5	5	1.5	MR5-2.5 MR5-2.5 ZZ
2.5	8	2.5	MR8-2.5 MR8-2.5 ZZ MR82x MR82x 2rs MR82xzz

Bore 3 to 4 mm

d	D	B	Models
3	6	2	MR63
3	6	2.5	MR63 2rs MR63 ZZ
3	8	3	MR83 MR83 2rs MR83zz
3	9	4	MR93 MR93 2rs MR93 ZZ
4	7	2	MR74
4	7	2.5	MR74 2rs MR74 ZZ
4	8	3	MR84 MR84 2rs MR84 ZZ
4	10	3	MR104B
4	10	4	MR104 MR104 2rs MR104B ZZ MR104zz

Bore 5 to 8 mm

d	D	B	Models
5	8	2.5	MR85 MR85 2rs MR85 ZZ
5	9	3	MR95 MR95 2rs MR95 ZZ MR95ZZ1
5	10	4	MR105 MR105 2rs MR105 ZZ
5	11	4	MR115 MR115 2rs MR115 2RZ MR115 ZZ MR115VV
6	10	2.5	MR106
6	10	3	MR106 2rs MR106 ZZ MR106ZZ1
6	12	4	MR126 MR126 2rs MR126 ZZ
7	11	2.5	MR117
7	11	3	MR117 2rs MR117 ZZ
7	13	4	MR137 MR137 2rs MR137 ZZ
8	12	3.5	MR128 MR128 2rs MR128 ZZ MR128ZZ1
8	14	3.5	MR148
8	14	4	MR148 2rs MR148 2RZ MR148 ZZ MR148DD MR148VV

Dimensions are the same as on each model page. In several sizes the shielded version is wider than the open one, so it is listed in its own row. Flanged MF bearings and inch R bearings have their own pages.

Design checks for miniature bearings

At these sizes a burr or a few microns of seat error changes clearance and torque. Keep shaft and housing seats clean, round and deburred.
The internal clearance is small. A heavy interference fit can remove most of it, so choose a light fit and check the clearance after mounting.
Grease type and fill amount have a large effect on starting torque and noise. State the torque or noise target when you ask for a quote.
In some sizes ZZ and 2RS versions are wider than the open bearing. Check B before you change the closure.

Custom MR bearings

We make MR bearings in chrome or stainless steel, with steel or ceramic balls, in open, ZZ or 2RS versions. Send the size, closure, clearance, grease, speed and quantity. Non-catalog miniature sizes can be made to drawing after a feasibility check.

Frequently asked questions

What does MR105 mean?

MR105 is a metric miniature bearing with a 10 mm outside diameter and a 5 mm bore. Its width is 4 mm.

What is the difference between MR105 and 695?

Both have a 5 mm bore. A 695 has a 13 mm outside diameter, so it has a thicker section and carries more load. An MR105 needs less radial space.

Should I choose ZZ or 2RS for a miniature bearing?

ZZ metal shields run with low friction. 2RS rubber seals give better protection where dust and moisture are the main risk.

Are MR bearings the same as R bearings?

No. MR bearings are metric. R bearings are inch sizes, for example R2 = 1/8 × 3/8 inch. They are not interchangeable.

Miniature bearing selection guide →Why miniature bearings feel rough or notchy →MR63ZZ bearings for galvo scanners →Thin-section bearings 6700, 6800, 6900, 16000 →Flanged miniature bearings →All deep groove and miniature bearings →

MR Miniature Ball Bearings: Metric Sizes from 1 to 8 mm Bore