ENGEL 20swg (1.0mm) BUTTON PUNCH SNAP LOCK ROLLFORMERS are 9 station machines and are principally used in the HVAC industry, for joining sheet metal at right angles on straight and curved duct sections. The female ‘Lock’ is formed in one pass and the flange, complete with the punched louvers is formed on the auxiliary side of the machine. Simply snap the flange into the female section. There is no knocking over of the edges as with the Pittsburgh Lock. (Ref:311).
This machine is now sold.