608-ZZ Bearings

10-pack of 608-ZZ double-shielded miniature radial ball bearings for 8 mm shaft/idler positions in 3D-printer motion projects, Polyformer builds, BeltDrivenEnder3 mods, and ERCF/Rabbit-style assemblies.

Why use ZZ instead of 2RS?

• ZZ means metal shields on both sides: lower drag than rubber-sealed 2RS bearings while still helping keep grease in and debris out.
• The standard 608 size is the common 8 mm bore bearing used in printed idlers, rollers, spool holders, and small mechanical assemblies.
• If the bearing will see dust, filament crumbs, or more contamination, use the rubber-sealed 608-2RS Bearings instead.

Specifications

• Pack quantity: 10 bearings
• Part code / MPN: 608ZZ / 608-ZZ
• Dimensions: 8 mm ID × 22 mm OD × 7 mm width
• Bearing type: single-row deep-groove radial ball bearing
• Closures: double metal shielded (ZZ)
• Typical material: steel bearing rings and balls with pressed-steel cage

Printer/project fit

• Useful as replacement 608-size bearings for Polyformer motion assemblies; see the Polyformer Bearings Kit if you want the project bearing set.
• Also tagged for BeltDrivenEnder3 motion use; pair with the BeltDrivenEnder3 Kit by kevinakasam when you are building or refreshing that mod.
• Fits generic 8 mm shaft/idler roles where the BOM calls for 608ZZ, 608-ZZ, or a shielded 608 bearing.

Gotchas

• These are not rubber sealed; for higher contamination protection, choose 608-2RS.
• These are not flanged and not a linear bearing.
• Confirm your BOM wants a 608-size bearing: 608 is 8×22×7 mm, not 625, 623, MR85, or LM8UU.