How to Choose Graphite Electrode Size: UHP Diameter and EAF Matching Guide

For EAF steelmakers, selecting the correct graphite electrode size directly affects smelting efficiency, consumable cost per ton of steel and production stability. Many overseas buyers ask during inquiries: What diameter graphite electrode should my electric arc furnace use? What is the difference between RP, HP and UHP grades? Based on years of manufacturing and supply experience, Handan Dongyuan Metallurgical Carbon has prepared this practical graphite electrode selection guide.

Graphite electrodes are classified into three grades by power level: RP (Regular Power), HP (High Power) and UHP (Ultra-High Power). RP electrodes suit small furnaces and ladle refining furnaces; HP electrodes fit medium-capacity EAFs; UHP electrodes are designed for large high-power EAFs, featuring lower resistivity and better thermal shock resistance for continuous intensive smelting.

As a general reference, Φ300–350mm electrodes match small furnaces under 10 tons and refining furnaces; Φ400–450mm electrodes suit medium EAFs of 10–30 tons; Φ500–600mm electrodes fit large EAFs of 30–80 tons; and Φ600–700mm electrodes are commonly used for UHP EAFs over 80 tons. Larger diameters provide greater current-carrying capacity for high-power input. Final selection should be confirmed against furnace design, transformer capacity, secondary voltage, operating current and melting practice.

Handan Dongyuan Metallurgical Carbon supplies full-range RP, HP and UHP graphite electrodes from Φ100 to Φ700mm together with matching high-precision nipples. We recommend suitable specifications based on your furnace model and smelting conditions. Every batch undergoes inspection on key indicators including resistivity, flexural strength and bulk density before delivery. Our products are used in EAF steelmaking and silicon submerged-arc furnaces, with bulk supply experience across Central Asia, the Middle East, Southeast Asia and other regions. Contact us for selection advice or detailed technical datasheets.