The most common and most likely answer to this crossword clue is the 5 letter word DRAIL
D
R
A
I
L
Buddy explains!
The straight part
We know that "Piece of lead finally fixed to bar" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case piece of lead finally fixed to bar = drail.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 DRAIL mean?
DRAIL noun- A hook with a lead shank.
- The piece of lead around the shank of such a hook.
- The iron bow of a plough from which the traces draw.
- To trail; to draggle.