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Curious Inventor - Store: Nibbler
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in stock - price: $10.99
Nibbler
Nibbler

short description:

Use this to "nibble" away up to 18 gauge (.046") steel or 1/16" copper, aluminum and plastic. Especially useful for making rectangular holes for DB9 connectors.

more information and instructions:

First, drill a 3/8" hole if not starting from an edge. Place the tool as shown so that it can bite off a small slug of metal.

A variety of shapes can be made, even including curves by rotating the tool slightly between bites. Right angles can be made by pulling the nibbler out, and then reinserting at 90 degrees. Follow up with a file to smooth the edges.