Deep holemaking

Machining graphite electrodes comes with its specific challenges and problems, with the most common being edge chipping. Experienced engineers have summarized the useful guidelines.

Both gundrill and BTA drills can reach almost endless depth. The deep holes created by gundrill can have excellent straightness and close tolerance, though at a relatively lower speed. Compared to gundrill, BTA drills can achieve larger diameters and higher feed rates, at a much lower cost.