Definition
A temporary sheet metal fastener used to hold two or more pieces of material in alignment through pre-drilled holes while permanent fasteners (such as rivets) are being installed. The Cleco is inserted into a hole and squeezed with a special pliers; internal spring-loaded jaws clamp the layers tightly together until removed.
Plain English
A small, reusable clip that holds metal panels together through their rivet holes while you set the real rivets. Think of it as a temporary stand-in fastener that keeps everything lined up during the job.
Context Anchor
Seen in aircraft sheet-metal repair, panel fitting, and rivet layout work, especially before permanent fasteners are installed.
Derivation
Named after the Cleco brand, originally made by the Cleveland Pneumatic Tool Company. The brand name became the everyday word for this type of temporary fastener, similar to how 'Band-Aid' became a generic term for adhesive bandages.
Why Pilots Care
On airframe inspections or repairs, Clecos keep panels and skins precisely aligned during riveting. Misaligned holes lead to weak joints, elongated holes, or rejected work, so understanding their role helps when reviewing maintenance or signing off repair work.
Analogy
Similar to how a paper clip holds sheets of paper, but designed for metal and strong enough for aircraft work.
Intuition Check
Do not treat a Cleco fastener as a finished aircraft fastener. It is a temporary holding tool used so the final fastener can be installed correctly.
Example Sentence 1
Before driving any rivets, the technician installed Cleco fasteners every few holes to hold the new skin panel tight against the rib.
Example Sentence 2
After positioning the new patch, Cleco fasteners were applied before final riveting.