[WOODPIE]

lendaddy,

I know very little, really, about EDM machining, other than I've seen a couple of them in operation, and I knew the machinist that wrote the programs, owned and operated them. This fellow built his business in a small out-building next to his house, contracting for tool and die work mostly, using the more conventional machining techniques when he started out. Very smart fellow in a field of smart fellows.

He bought his second, larger, EDM within a year after buying the first one; he was so impressed with the increase in productivity. He added on to his existing space to house the machines and enlarged his measuring room. The parts cut on the EDM required minimal amounts of secondary machining to make them usable in his progressive T&D blocks, or whatever you call them.

I used to have a piece of scrap tool steel he gave me. It measured about 2.5 X2.5 X 3 inches, and it had four identical "U" shaped holes cut straight through the 2.5" thickness. The finish was very smooth and consistent, but wasn't a ground or polished kind of finish.

Reading through this, I'm doubting that I've told you anything you didn't know already if you're in the metal working business, but, hell, nobody else had much to say.

Ed