Three bearing types cover almost every hobby build: the 608 for spinning, the flanged bearing for small housings, and the linear bushing for sliding. This guide tells you which one your project needs.
608 ball bearings: the spinning workhorse
The 608ZZ / 608RS ball bearings measure 8mm bore x 22mm outside diameter x 7mm wide, pre-lubricated, in a 10-pack. Choose 608ZZ with metal double shields, or 608RS with rubber seals for dust-proof, maintenance-free running. They fit skateboard and inline skate wheels, 3D printer and CNC builds, electric motors, fidget spinners, and other small machinery. Buy them for idlers, pulleys, wheels, and anything that spins on an 8mm shaft.
Flanged bearings: small housings
The F623ZZ / F624ZZ / F625ZZ flanged ball bearings are for small shafts in tight housings: F623zz 3x10x4mm, F624zz 4x13x5mm, F625zz 5x16x5mm, or F626zz 6x19x6mm, in GCr15 bearing steel. The flange holds the bearing in place in its housing, so no separate retaining clip is needed. Buy them for 3D printer and CNC builds, small motors, and robotics where the bearing has to stay put in a printed or machined pocket.
Linear bushings: sliding axes
The LM8UU / LM6UU linear ball bushings are the standard way to build X, Y, and Z axes on 3D printers and CNC machines. LM8UU for 8mm shafts (8mm bore, 15mm outside diameter, 24mm long) or LM6UU for 6mm shafts (6mm bore, 12mm outside diameter, 19mm long). The recirculating ball design glides along the shaft with minimal play. Pair them with the SK8 / SK10 / SK12 / SK16 linear shaft supports — four supports per pack, one at each end of the shaft, in 8, 10, 12, 13, or 16mm sizes.
How to choose
Spinning on a shaft: 608. Small shaft in a housing that needs to stay put: flanged. Sliding along a shaft: linear bushing. Match the bore to the shaft first — a 608 is always 8mm, flanged sizes run 3 to 6mm, and bushings come in 6 and 8mm here. Check the product pages for the current sizes before you order.
All parts in this guide ship from NY, USA. See the full list of guides on the Drone Guides page.
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