Tear when getting something from the tool box (6)

I believe the answer is:

wrench

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'tear' is the definition.
(wrench can mean to tear or pull)

I don't understand how the rest of the clue works.

(Other definitions for wrench that I've seen before include "Kind of spanner or severe twist" , "Sudden violent twist" , "Sprain - difficult parting" , "Jerky pulling movement" , "Sort of spanner - twist it" .)

I've seen this clue in the Evening Standard.

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