巩

Left work radical — pictograph of a carpenter's square, the basic measuring tool. The radical anchor for 巩 in dictionary indexing. Carries a faint semantic bonus: to consolidate or strengthen something is to do real working-on-it labor. Same family: 巧 skillful, 左 left, 差 to lack.

Right 凡 supplies the sound — fán shifting to gǒng via the substitution that happened when 鞏 was simplified, 凡 replacing the heavier 巩-traditional structure. The traditional 鞏 was 巩 over 革 (leather) — leather strapping reinforcing a frame. The simplified version keeps just the working-tool side, with 凡 as a brief phonetic placeholder.