[asid61]

We use two calipers. One is in the machining tool box, where everything is nice and sorted and clean (and I like to keep it that way), and the other is in the communal toolbox, where things get bumped around with the rulers and the like. Both are in their own boxes. However, even after ~5 or 6 years of constant use, the ones in the communal toolbox are still accurate to +- 0.001", or better. Both are Brown and Sharpe dial calipers bought for about $100 each years ago by one of our mentors. Good tools last, as long as students are told how to use them properly.