螺丝
luó sī · HSK 7
screw
🔩 螺 spiral + 丝 thread = a screw, the spiral-threaded fastener
螺 means spiral or snail-shell, and 丝 means thread or fine wire. A screw is exactly that: a spiral thread cut into metal. Sound: luó sī, the second syllable echoes the s-sound of silk (丝).
丝 — two 糸 silk threads side by side
丝 is a pictograph showing two bundles of silk threads (糸) twisted together, representing raw silk. The original form depicted skeins of silk on a spindle. It later broadened to mean any fine thread or filament, and figuratively a tiny trace or amount.