http://www.proz.com/kudoz/german_to_english/p...
It takes a sharp axe to split a tough log / You have to give it straight from the shoulder / It's no good mincing words

http://www.recmusic.org/lieder/get_text.html?...
In the New Year
In the new year, fortune and health!
For grief and pain a decent cure!
From coarse oafs some effective distance!
And one and a half times that from a rogue!

Pons-Collins:
grob - ...
auf einen groben Klotz gehört ein grober Keil - (Prov) one must answer rudeness with rudeness

Auf groben Klotz ein grober Keil!
>>From coarse oafs some effective distance!

Um ... Is that Emily what's-her-name's lieder page? Something seems to have gotten lost in that 'translation.'

>>It takes a sharp axe to split a tough log

Closer, sort of, but is a 'grober Keil' really a sharp axe?

Whether the proverb originated with Goethe or earlier, the point of the joke seems to be that Klotz means block, lump, etc. not only in the sense of a chunk of wood, but also in another sense meaning a dull-witted person. Both those words were still used in that sense in English in Goethe's day, but nowadays we would probably need another word, like a blockhead. I suppose you could try something like 'It takes a coarse axe for a coarse lump,' but I'm not sure anyone would get it.

I keep thinking there's some other saying that's vaguely similar, maybe in the direction of tough problems requiring drastic remedies, or needing a stronger tool for a tougher job ... But that's still not very close; it's not even on the tip of my tongue, it's buried somewhere deep in my mush for brains, sorry. Maybe it will ring a bell with someone else.

... was sich statt eines groben Keils auf einen groben Klotz setzen läßt, erfährt man in diesem Faden ab #25:

Siehe auch: Rosettenkönig (Tourette) - #25 . . .

Wie wär´s mit "desperate times call for desperate measures"? Aber das bezieht sich halt mehr auf eine Situation als auf eine Person.