Engineering material used for weighing by the yard!
I believe the answer is:
steel
'yard' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Maybe you can see a link between them that I can't see?
'engineering material used for weighing by the' is the wordplay.
I cannot quite understand how this works, but
'engineering' could be 'ee' (EE is an example) and 'ee' is found in the answer.
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is found within the answer.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for steel that I've seen before include "Hard iron alloy" , "Hard, strong, grey alloy" , "Iron/carbon alloy" , "The staying power" , "Knife-sharpener" .)