The Virtual Machine Shop

Fit

Refers to a class of size matches between two similar but opposite geometries and usually applies to cylindrical fits. The two most common types of fits are slip-fit and press-fit. A dowel pin is said to have a slip-fit with a reamed hole if it can slide snugly through the hole. It is said to have a press-fit with the reamed hole if pressure needs to be applied to push it into the hole. The physical amount of slip and press is governed by the "class" of the fit, which can be found in the Machinery's Handbook.