MR85-ZZ Bearings

10-pack of MR85-ZZ miniature shielded ball bearings. These are the compact 5 mm ID × 8 mm OD × 2.5 mm width deep-groove bearings used anywhere a small 5 mm shaft needs low-friction support in a tight printed assembly.

Why use MR85-ZZ here

• Correct miniature size: MR85-ZZ / MR85ZZ format, also cross-referenced as L850ZZ or R-850ZZ by bearing suppliers.
• Metal shields on both sides: ZZ shields help keep dust and printed-plastic debris out while staying lower-drag than contact rubber seals.
• Chrome-steel construction: supplier datasheets list SAE 52100 chrome-steel rings and balls with a pressed-steel cage.
• Pre-lubricated: ready to install for light-duty printer, robotics, and hobby motion assemblies.

Specifications

• Quantity: 10 bearings
• Designation: MR85-ZZ / MR85ZZ
• Bore / inner diameter: 5 mm
• Outer diameter: 8 mm
• Width: 2.5 mm
• Closure: metal shielded both sides (ZZ / 2Z)
• Material: SAE 52100 chrome steel rings and balls; pressed-steel cage
• Typical reference speed: 53,000 rpm with adequate lubrication, per SMB Bearings MR85ZZ datasheet

Fitment notes

• Use these when your BOM calls for MR85-ZZ, MR85ZZ, L850ZZ, or R-850ZZ.
• Keep a spare pack with small-format printer builds; the live Voron V0.2r2 Upgrade Kit listing calls out one MR85zz bearing.
• If you are rebuilding leftover ERCF v1/v1.1 hardware, cross-check the bearing callouts against the Rabbit Poop bundle notes before ordering extras.

What it is not

• Not a rubber-sealed 2RS bearing; choose 2RS only where your application needs contact seals over lower drag.
• Not a flanged bearing and not a 623-size bearing. For other miniature bearing formats, compare the bore, OD, and width before substituting.