sword guard, kettle brim
鍔 centers on a protective metal rim or flange: the guard of a sword or the brim of a kettle. Both senses describe a projecting metal edge that shields or contains.
鍔 combines 金 (metal) with 咢, which likely contributes the sound. The character refers to a metal rim or guard, consistent with the metal radical.
The left side is metal 金, and the right side 咢 looks like a mouth 口 under a cover 二 with a wrapping stroke 勹. Picture a metal guard shaped like a protective jaw around a sword or a kettle's brim.
For ガク, imagine a sword guard shaped like a gak (a made-up sharp metallic sound) that rings when struck: gak -> ガク, and the metal guard protects the hand.
guard (on a sword)
two things that do not go well together; pairing kintsuba with loach soup
confection of sweetened beans wrapped in wheat-flour dough (in the shape of a sword guard)
confection of sweetened beans wrapped in wheat-flour dough (in the shape of a sword guard)
wide brim (e.g. of hat)
sound when stopping the blade of a sword with the guard