An F623 bearing seats in a Ø10.008 mm housing bore for a drop-in slip fit (ISO 286 H7), or Ø9.989 mm for a light press fit (N7).
A bearing's outer ring is toleranced 0/−Δ per ISO 492, so the housing bore decides the fit. An H7 bore leaves clearance: the bearing drops in by hand and needs a shoulder or circlip to stay put — the standard choice when the outer ring is stationary and the shaft rotates. An N7 bore gives light interference: the seat itself holds the bearing captive, at the cost of needing press force and a little preload.
A printed housing rarely comes out at the commanded size, and a bearing pocket is exactly where that error shows — a few hundredths undersize turns a slip fit into a press fit, and oversize lets the outer ring spin in the bore. Measure your machine's error once and every number on this page moves with it.
Metric clearances per ISO 273 · imperial per ASME B18.2.8 · heat-set pockets per CNC Kitchen · bearing housing seats per ISO 286. Reference only — verify before you cut.