WHOLE CHARACTER
铁tiě
iron (the metal); firm; unshakable; stern; unsmiling (of a face); weapons (old use)
铁 is iron: 铁路 'railway', 地铁 'subway', 钢铁 'steel and iron'.
ZDIC header names only a generic 形声 account with no parts. The modern shape shows the metal side 钅 (the source's listed radical) with 失 at the right; the traditional form 鐵 (given in the source's variant note) has a different, fuller right side, so no sound story is claimed for 失.
LEFT: THE METAL SIDE — IRON IS A METAL (THE SOURCE'S LISTED RADICAL)
钅jīn
metal; gold (from 金)
The left-side metal form; not a standalone page.
In 铁: left: the metal side — iron is a metal (the source's listed radical) Shown with its documented or clearly limited role.
RIGHT: THE WRITTEN RIGHT PIECE
失shī
to lose; to miss
A standalone character (shī, to lose); where its shape appears as a written piece, that page states the written role and any limits.
In 铁: right: the written right piece No sound hint claimed: 失 (shī) shares no sound part with tiě — the initials (t-/sh-), finals (-ie/-i) and tones (3/1) differ.