Yep, I've done it. I've broken a brand new set of carbon bars by over torquing the brake bolts. Birzman neatly eliminates that problem with this, their M-torque 5Nm folding tool. The little button on the right side of the tool is the torque measure. Simply tighten the bolt in question while pressing that button; at proper torque, the button pushes in. Brilliant. Your only excuse for breaking a carbon component now is pure idiocy. I bought one on the spot.