Imagine a hand tool about 7 or 8 inches long, shaped like a narrow V
One side of the V
is the body of the tool, and the other side is the
operating handle. You hold the tool in one hand, and feed the sheet metal
material with the other hand.
The working end of the tool consists of a
small anvil, formed by the body of the tool, with a shaft running through
the body, connected in lever fashion to the operating handle.
Squeezing the operating handle would pull the shaft, which had
mounted on it a spring loaded clamp (to hold the sheet brass material
against the anvil), and a blade (to cut off a small chunk of material).
A big bite was about one quarter inch wide (the width of the cutting blade),
and one sixteenth deep, and you could take bites like this without curling
or distorting the material, in brass up to .063 inch thick. You could do
square corner cutouts in floppies and need only minimal cleanup with the file.
You could do square or rectangular holes in drop arms by drilling one hole
in the center big enough to fit the clamp and blade through, and then cutting
out all the rest with the tool. Clever, huh? Ka-chunk, ka-chunk, ka-chunk.
The tool is called a "Nibbler" and the process is called "nibbling".