Definition
A class of mechanical fit in which two mating parts are sized so one can be inserted into the other by hand or with light hand pressure, without the use of tools, heat, or significant force. The clearance between the parts is small but positive, allowing assembly and disassembly without damage while still providing close alignment.
Plain English
A push fit is when two parts are sized so one slides into the other using just hand pressure — not loose enough to fall out on its own, but not so tight that you need a press, hammer, or heat to get it in.
Context Anchor
Seen in aircraft engine maintenance instructions when parts such as sleeves, pins, or similar fitted parts must be installed with a specific tightness.
Why Pilots Care
Knowing whether a part is specified as a push fit, slip fit, or interference fit tells the technician how it should go together. Forcing a push-fit part with a press, or pushing in an interference-fit part by hand, both indicate something is wrong — wrong part, wrong size, or a worn hole.
Intuition Check
Push fit does not mean any part you can shove into place. It means the parts were intentionally sized to fit together with light pressure and proper alignment.
Example Sentence 1
The bushing is a push fit in the housing, so the technician seated it with hand pressure rather than using the arbor press.
Example Sentence 2
Technicians checked that the fuel line fitting remained a push fit after repeated removals.