The game is the manufacturing and application-related freedom of movement in which a mechanical component can be moved freely during or after assembly against another component or with another component, the assembly or functional unit. In the case of roller bearings , we speak of clearance instead of play .
A nut can only be easily fitted onto a screw if there is a sufficient air gap between the two threads. The initially existing play allows threads that are not ideally shaped to slide past one another and that the nut can adjust itself slightly at an angle to the thread when tightened on a non-ideally transverse counter-bearing or a slightly bent screw.
A door with a certain leaf thickness requires a certain radial frontal play between the door leaf and the frame in order to be able to rotate out of the door opening without being wedged. Sufficient play between the floor and the underside of the door is necessary so that a grain of sand does not rub, and so that the floor can bulge without damage under the impact of foot traffic and changes in humidity and temperature. Too much door clearance can have undesirable consequences: Insufficient sealing against drafts, light shining through despite the fold (stepped profiling) of the door leaf and / or door frame.
If a refrigerator or washing machine is to be pushed into a gap in one or between pieces of furniture, it needs at least a few millimeters of clearance so that it does not tilt quickly. The same applies to a hooded lid on a shoe box or the sheet metal lid of a canning jar.
In the case of bicycles, the bearing play (the bearing clearance ) on the conical bearings must be set in such a way that, although easy turning is possible, the supported part does not "slither" loosely.
A suitable game between two individual parts can be achieved by suitable tolerancing of the individual parts.
For the individual parts concerned, a large play usually means ease of movement, problem-free assembly, avoidance of tension, insensitivity to temperature fluctuations and contamination, possibly less noise and more predictable behavior during operation, but also low position accuracy and often greater wear. Under certain circumstances it makes sense to set the tolerances of the individual parts in such a way that there is very little play between the parts or even an interference dimension (press fit, press fit ).