624ZZ Miniature Radial Ball Bearing - 4x13x5mm Double Shielded

Specifications

• Model Designation: 624ZZ

• Bearing Type: Deep Groove Radial Ball Bearing

• Inner Diameter (Bore): 4mm

• Outer Diameter: 13mm

• Width (Thickness): 5mm (Standard for 624 series)

• Shield Type: ZZ (Double Metal Shields)

• Material: Bearing Steel

• Lubrication: Pre-lubricated (Grease)

Key Applications and Projects

• 3D Printers & CNC Routers: Pressed inside plastic or polycarbonate V-slot wheels to allow the gantry axes to glide smoothly along aluminum extrusions.

• Timing Belt Idlers: Acting as the smooth spinning core for custom GT2 timing belt pulleys and tensioners in automated machines.

• RC Vehicles & Drones: Serving as lightweight, low-friction wheel and gearbox bearings for 1/16th or 1/24th scale remote control cars and helicopters.

• DIY Robotics: Creating smooth, low-friction pivot joints for miniature robotic arms or custom mechanical linkages.

Unlock New Capabilities (Project Evolution)

• The Ultra-Smooth Macro Camera Slider: Professional motorized camera sliders can be incredibly expensive. Evolve your cinematography by building your own! By pressing four 624ZZ bearings into Delrin V-wheels, you can mount them to a custom 3D-printed carriage that glides effortlessly along a 2020 aluminum extrusion. Pair it with an N20 motor or a stepper motor and a GT2 timing belt (using two more 624ZZ bearings as smooth idler pulleys), and you have a motorized, whisper-quiet slider for capturing stunning, jitter-free macro timelapses!

Package Includes:

• 1 x 624ZZ Radial Ball Bearing (4x13x5mm)

FREQUENTLY ASKED QUESTIONS (FAQ)

1. What does "624ZZ" mean? "6" signifies a deep groove ball bearing. "2" denotes the dimensional series. "4" indicates a 4mm bore size. "ZZ" means it has metal shields on both sides.

2. What is the inner diameter (bore) size? The inner hole is exactly 4mm in diameter.

3. What is the outer diameter? The outer ring is 13mm in diameter.

4. How thick is this bearing? The standard width/thickness for a 624ZZ bearing is 5mm.

5. Do I need to grease or oil these? No, the ZZ shields mean the bearing is packed with grease at the factory and permanently sealed. Adding liquid oil can actually wash out the intended grease.

6. What is the difference between ZZ and 2RS? ZZ bearings use metal shields that do not touch the inner ring, resulting in very low friction but slightly less dust protection. 2RS bearings use rubber seals that physically rub against the ring, providing a watertight seal but causing drag/friction.

7. Are these bearings waterproof? No. While the metal shields keep out dust and debris, water can easily seep past them and rust the internal steel balls.

8. Can I use this for axial (thrust) loads? Deep groove ball bearings are designed primarily for radial loads (forces perpendicular to the shaft). They can handle very light axial loads (forces parallel to the shaft), but heavy axial loads will cause premature wear.

9. Are these the bearings used in standard skateboard wheels or fidget spinners? No. Skateboards and most standard spinners use 608 series bearings, which have an 8mm bore and 22mm outer diameter. The 624ZZ is much smaller.

10. Can I remove the metal shields? Yes, you can carefully pry them out with a needle or fine craft knife if you need an open bearing or want to flush it with a different lubricant, but it will expose the balls to dirt.

11. How do I properly press-fit this bearing into a housing? When pressing the bearing into a 13mm hole (like a 3D printed part or wheel), only apply pressure to the outer metal ring. Pushing on the inner ring will crush the balls against the raceway and damage the bearing.

12. How do I press it onto a shaft? When pressing it over a tight 4mm shaft, only apply pressure to the inner ring.

13. Why does my bearing feel "gritty" when I spin it? Grittiness usually means dirt has bypassed the shields, or the bearing was damaged during installation (e.g., pressed in by the wrong ring). It should be replaced.

14. Is this bearing magnetic? Yes, standard bearing steel is magnetic.

15. What RPM can this handle? Due to its miniature size and metal shields, the 624ZZ can comfortably handle speeds exceeding 30,000 RPM under light loads.

16. Can I use these to replace the bearings in my 3D printer's V-wheels? Yes, the 624ZZ is the exact standard bearing used inside most standard polycarbonate and Delrin V-slot wheels (such as those found on the Creality Ender series). You typically need two bearings per wheel.

17. How much weight can a single 624ZZ bearing support? While the static load rating is around 300 Newtons (approx. 30 kg / 66 lbs), for dynamic (moving) applications and maximum lifespan, it is best to keep the continuous load per bearing under 5-10 kg.

18. Can I clean these bearings in an ultrasonic cleaner? If you do, the solvent will wash away the factory-applied internal grease. Because the metal shields (ZZ) cannot be easily removed and reinstalled without permanently bending them, it is extremely difficult to re-pack them with thick grease properly afterward.

19. What is the maximum operating temperature? Standard bearing steel and factory grease can typically withstand continuous temperatures up to roughly 120°C (248°F) before the grease begins to degrade and thin out.

20. Do these bearings have a "break-in" period? Yes. Brand-new bearings packed with fresh grease can sometimes feel slightly stiff when spun by hand. Running the bearings under a light mechanical load for a few hours will distribute the grease evenly and help them achieve maximum, frictionless smoothness.