The metal radical (left-side form of 金) marks 铅 as one of the metallic elements. It heads the chemistry family of metals - 铁 iron, 铜 copper, 银 silver, 锌 zinc - where 钅 frames a phonetic that names which metal.
The top portion of the right side approximates a 几 shape and contributes the upper half of the phonetic stem 㕣. Its standalone reading is incidental; here it is recruited mainly for its visual silhouette and supporting sound role.
Closes the lower half of the right side. Together with the 几 above it forms a phonetic unit historically read as a sound related to lead, linking 铅 to 沿 and 船 which share the same right-side compound.
