armor neckplates
錣 centers on a specific piece of armor: the neckplates that protect the neck area. It is a narrow, concrete term without broad abstract extensions.
錣 combines 金 (metal) with 叕, which likely contributes the sound. The character specifically denotes metal neckplates for armor.
The left side 金 (metal) and the right side 叕 (a shape suggesting linked pieces) together picture metal plates linked to protect the neck: armor neckplates.
For テツ, imagine a blacksmith hammering metal plates, making a sharp 'tets' sound with each strike: tets -> テツ, and the metal becomes neck armor.