I started at strength eight, but the watered cane was a bit too soft. Probably I also got somewhat used to the cane again. Therefore I increased the strength setting of the machine up to its maximum. It wasn't enough and after twentyone dozen hits with the cane I set the machine to 100 more hits. But after only 30 or so hits the cane broke and i had to stop. Eight millimeter cane, machine at strength eight increasing to maximum.