The most common and most likely answer to this crossword clue is the 8 letter word TINPLATE
I've seen this crossword clue in Financial Times
T
I
N
P
L
A
T
E
More clues leading to the result TINPLATE
Buddy explains!

The straight part
We know that "Can metal" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case can metal = tinplate.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does TINPLATE mean?
TINPLATE noun- A thin sheet of steel coated with tin to prevent rusting; used to make cans etc.
- To coat (something, especially steel sheet) with tin, either by dipping or electroplating.