For a 200 mm graphite electrode, roughly 6–10 kA can serve as an initial screening range for some EAF applications. It is not a universal rating. The allowable current depends on electrode grade, manufacturing quality, nipple connection, furnace practice, and cooling conditions. A 1,800 mm length does not determine the current capacity by itself.
Check the supplier’s technical data for maximum continuous current, bulk density, resistivity, and permitted current density. Then compare those figures with the furnace transformer, secondary circuit, and operating schedule.
During a heat, watch for connection heating, unusual oxidation, and uneven wear near the electrode tip. Small details matter. A rating that looks suitable on paper may not fit a furnace with frequent power changes.
For China-based manufacturers, request test data tied to the offered production batch, not only a general catalogue. Confirm whether the stated kA value is continuous or short-term, and ask how it was determined. Keep a cautious margin during commissioning, then review actual electrode consumption and joint temperatures. I would not rely on diameter alone; even a neat specification sheet can leave practical questions unanswered.