To drill a long hole, mark the material with a scribing iron or a sharp pencil. Then punch several drill holes right next to each other depending on the required length, drill them out, and file the long hole with a round file to suit the diameter of the holes. To finish, you can file off with a suitable flat file.
More information: http://products.alfer.com
The title is a bit misleading, I assumed it was about drilling deep holes (i.E. Gunn drilling).
123HURST 4 months ago
Call me old fashioned, but I believe the technical term is a "slot"!
TheGreybelly 5 months ago 2