I have a pair of brake drums off of a 44,000 mile truck. The shoes looked great, but the chassis was going under something else, so the owner wanted new shoes and wheel cylinders. One rear drum had a little warp and created a noise at slow stopping speeds. Took the drum in to get turned, only one of 6 parts stores in town turns drums now. and then only one guy. The drums only have .060 that they can be turned (even new off the shelf), The 1st cut only cut about 1/4 of the drum. The 2nd cut cleaned up about 3/4 of the drum, The 3rd cut cleaned up the entire braking surface, but that cut was not smooth. The guy took one more small cut to try to clean up the surface, after he replaced the cutting tool. It was just slightly better, but I took it home, it was just under specs. The guy did not charge me to turn that drum ($20 normal cost). My cost on a replacement drum was $60 (the local store was cheaper then what was available on line right at the time), but would have had to be ordered. Before Dec I priced out those drums and they were only $42 each then, but the week later the price jumped to $60. The front rotors only have an allowable .060 cut as well, try getting a warp out of a rotor in a .060 cut once, at .060, you would be lucky to get a smooth cut on both sides from a rotor that wasn't warped. By the way, its cheaper these days to buy a rotor kit, (both rotors, and pads), then it is to buy just rotors. You can get the master front brake kit that included calipers and hardware as well as the rotors and pads for less the the calipers and the rotor kits separately.

If the brake noise come back, the customer gets new drums, at whatever they cost then. I spent a couple hours jacking with that drum for a questionable return. Would have been more cost effective to order the new drums before the project started.