Better dies via electricity - WIP - Brief Article - Statistical Data Included

Automotive Design & Production, Sept, 2002

The company is called form Grinding. It is based in Troy, Michigan, It produces tooling for the auto industry, fooling as in dies that are used to produce components, such as fasteners via cold forming. One of the challenges that the company faced was creating the carbide inserts used for the dies. As the name of the company might imply, they were using grinding. Carbide--which is harder than steel-is challenging to work with. As Mike Selimi, mill leader at form Grinding, observes, "Most machine shops and die/mold operations don't like to deal with carbide because it is so tough to grind or work with. All you could do to prepare it For processing was to grind it with diamond grinding heads. And that is a dirty, dirty, job, as well as a costly and time-intensive one,"

So what to do as an alternative to using a grinder? Electricity was the answer. Electricity as in electrical discharge machining (EDM). Form Grinding obtained two machines, a U32 wire machine with a 12-pallet changing system and an Edge 2 RAM sinker-type machine, both From Makino (Mason, OH).

The wire machine is used to prepare and form the 2-in, long carbide workpieces. "We can run 50 jobs overnight with unattended machining," Selimi says.

Following that, the ram machine is used to give the head of the bolt its shape. "We used to get the hex bolt form by using six small, square inserts and grind them and work them to place inside of a ring to form that shape," notes Selimi. "Now we take a piece of carbide, which is put in that ring, and we rough it with the RAM to create the hex. The sinker allows us to eliminate grinding the cylindrical bolts, and to process the heads on the hex bolts, which saves time. Plus, we're able to get a superior Finish quality utilizing EDM technology." In the case of the wire machine, they're obtaining a 2- or 2.5-micron finish in three passes; with the sinker, they're getting a 4-micron finish.

To learn more about Makino EDM, write in 120 on the Reader Service Card.