I have a rather odd problem, that's recently shown up, never experienced it before. The teeth on my saw blades are literally wearing off! Very quickly too. I am using a 2/0 bade on 1.2mm sterling sheet which I have done plenty of times before, but I have literally gone through 5 saw blades and managed to saw 1cm. I'm using a little beeswax to lubricate. Any ideas, it's drivng me batty!!??