炼
liàn · HSK 7
chain; variant of 鏈|链[lian4]; variant of 煉|炼[lian4]
🔥 炼 = fire radical 火 + 柬; to refine or smelt metal with fire
The 火 fire radical on the left drives the meaning: heating ore to refine it. Sounds like lian; also a variant for 链 chain, the forged result of all that smelting.
炼 — fire radical 火 + 东 (phonetic)
Originally written 鍊 with the metal radical 金, meaning to refine or smelt metal by fire. The modern simplified form 炼 uses the fire radical 火 to show the heating process, with 东 as a phonetic component derived from 柬. The meaning extended from refining metal to training, tempering, or honing skills.