Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.
When a project demands a compact, corrosion-resistant rolling element that fits where standard bearings cannot, engineers, hobbyists, and repair technicians reach for miniature deep groove ball bearings. Undersized housings, moisture-prone environments, and high-cycle mechanisms all expose the limits of carbon-steel alternatives — stainless steel ZZ-sealed bearings solve each of these pain points in a single part.
These miniature deep groove ball bearings are manufactured from stainless steel with double metal shields (ZZ designation) and are available across 31 size codes spanning inner diameters of 3 mm to 9 mm (approximately 0.118 in to 0.354 in). Outer diameters range from 7 mm to 28 mm (0.276 in to 1.102 in) and widths from 3 mm to 9 mm (0.118 in to 0.354 in), covering the 600-series, 620-series, 630-series, 680-series, and 690-series designations.
Typical use cases include RC car and drone pivot points requiring low-friction miniature bearings, 3D printer carriage and extruder assemblies where compact deep groove ball bearings reduce play, medical and laboratory instrument spindles that need corrosion-resistant miniature bearings, and small electric motor and gearbox rebuilds calling for ZZ-sealed stainless steel replacements.
| Bearing Type | Deep Groove Ball Bearing |
|---|---|
| Shield Type | ZZ (Double Metal Shield, Both Sides) |
| Material | Stainless Steel (rings, balls, shields) |
| Inner Diameter (ID) | 3 mm – 9 mm (0.118 in – 0.354 in) |
| Outer Diameter (OD) | 7 mm – 28 mm (0.276 in – 1.102 in) |
| Width | 3 mm – 9 mm (0.118 in – 0.354 in) |
| Size Series Available | 600, 605, 620, 623–629, 634–636, 638, 683–689, 693–699 |
| Lubrication | Factory-greased (sealed, not re-lubricatable without shield removal) |
| Operating Temperature | See variant options |
| Max Speed | See variant options |
| Load Rating | See variant options |
| Quantity per Pack | 1 / 5 / 10 / 20 / 50 Pcs (select above) |
Measure the shaft diameter (this equals the bearing inner diameter), the housing bore (this equals the outer diameter), and the available axial space (this equals the width). Match all three dimensions to the size code listed in the variant options — for example, 608ZZ has an 8 mm ID, 22 mm OD, and 7 mm width. If you are replacing an existing bearing, the size code is usually stamped on the outer ring.
ZZ (also written 2Z) indicates that both sides of the bearing are fitted with non-contact metal shields. The shields retain factory grease and prevent coarse particle ingress. They do not form a full contact seal, so these bearings are not suitable for submersion or high-pressure wash-down environments. For those conditions, a rubber-sealed (2RS) variant would be more appropriate.
Stainless steel construction provides meaningful resistance to oxidation and mild corrosion from humidity, light moisture, and non-aggressive chemicals. They outperform standard carbon-steel bearings in damp conditions. However, they are not rated for continuous immersion in saltwater or exposure to strong acids or chlorides. For marine or chemical environments, confirm compatibility with your specific exposure conditions before ordering.
Yes. These are among the most common replacement bearings for 3D printer carriage rails, extruder idlers, and hotend cooling fans, as well as RC car wheel hubs, steering knuckles, and drone motor mounts. Verify the exact ID, OD, and width required by your specific printer or vehicle model before selecting a size. The 608ZZ (8 × 22 × 7 mm) is particularly common in FDM printers, while smaller codes such as 603ZZ and 683ZZ suit micro-RC and drone applications.
For a one-off repair, a single piece (1 Pcs) is sufficient. If you are servicing a machine with multiple bearing points of the same size — such as a printer with four carriage bearings — ordering a 5- or 10-piece pack reduces per-unit cost and gives you spares for future maintenance. The 20- and 50-piece packs are suited to small production runs or workshop stock where the same size is used repeatedly.
Bearings with identical ID, OD, and width dimensions are dimensionally interchangeable regardless of series designation. For example, 604ZZ (4 × 12 × 4 mm) and 624ZZ (4 × 13 × 5 mm) share the same ID but differ in OD and width, so they are not interchangeable. Always compare all three dimensions — not just the inner diameter — when substituting one series for another.
Yes, all bearings are factory-greased before the ZZ shields are pressed into place. Under normal operating conditions, the factory grease is sufficient for the bearing's service life. Re-lubrication requires carefully prying off one shield, applying a small amount of compatible bearing grease, and re-seating the shield — a process that risks shield deformation. For most miniature bearing applications, replacement is more practical than re-lubrication when the bearing shows signs of wear or noise.
