General Cleco pins

Cleco (originally Avdel) pins, are used in sheetmetal fabrication, for clamping sheets together, through holes, usually subsequently opened out accurately for rivetting. They can be installed and removed very fast... wing nut and hex-nut versions clamp slightly better but are much slower to use..

They can be useful when fabbing, to keep sheets aligned, job in-place, and holes subsequently spot-MIG'd up