This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
鐴 combines 金 (metal) with 辟, which likely contributes the sound. The exact historical development is uncertain.
The left side is metal 金, and the right side 辟 looks like a complex tool. Picture an old metal implement whose purpose is now forgotten.
For ヘキ, imagine a metal tool making a sharp 'heki' sound when it strikes stone: heki -> ヘキ.