Pushes the tip off and induces corrosion (7)
I believe the answer is:
thrusts
'pushes' is the definition.
(thrusting is a kind of pushing)
'the tip off and induces corrosion' is the wordplay.
I cannot really see how this works, but
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is present in the answer.
'corrosion' could be 'rust' (rust is a kind of corrosion) and 'rust' is found within the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for thrusts that I've seen before include "drives" , "forces" , "jabs" , "Impels" , "Sudden lunges" .)