Any national chains offer drum grinding?

Do you mean turning or arching shoes to drums.Here few machine shops turn drums anymore.As for arcing shoes to drums last guy that did it her quit like 20 years ago.Chains usually have noone or equipment to turn drums.Some repair shops still turn them

I've never heard the term grinding drums before, but I will tell you sometimes places you thought quit doing it decades ago are still actively doing it. Call some area dealerships and local garages, you'll be surprised

We still teach it at a Tech School level and any decent shop should have a lathe capable of doing it......whether they have a tech capable...that's another question.

Any decent front end and brake shop should be able to turn them
Some of the cheaper aftermarket drums come close to being at the max size to start with new

My local O'Rielly still turns drums/rotors

Haven’t seen a drum grinding attachment in quite a while. Better shops had them and the brake lab at Chrysler did too.
Oval and road race teams always ground the drums back then from what I was told.

Last I knew (several years ago), my local O'Reilly's did as well.

They ‘turn’ drums no grinding process at all. A carbide bit cuts the drum till it’s smooth and straight again. I’ve done quite a few

i have a mandrel that fits a lathe, having a register the exact size of the axle/hub factory register. it is also the diameter [actually a little larger] of the hub/axle the wheel bolts to, so that the drum [or rotor] being turned is retained as it would be with the wheel bolted to it.
as a machinist, i feel this gives a better result than the parts store "cone shaped" locating device that just picks up the center hole of the drum/rotor being turned.
i also use a much larger cutting tool, which not only gives a much better surface finish, [being a substantially more rigid tool] it also doesn't "bounce around" like the tiny [in my opinion] cutting tools used with the parts store machines, thus giving a much truer diameter to the finished drum and a much flatter surface to the finished rotor.

first measure the inside dia. to make sure there still in spec. before having them machined,if out of spec their junk.

Who else here doesn't have such a lathe setup?

You don't know what you are missing?

How about a cnc mill? Even better!

Agree, I find something new to do on both the lathe and end mill almost everyday! I took your advise and now setting up a front wheel hub to cut my drums

i know most do not have this type of equipment at home, but being a machinist and fabricator by trade, once retirement hits, one usually wants to continue with his trade. this almost dictates one to purchase, or have access to, equipment he has "played with" over the course of his working career.
this is similar to guys who have woodworking equipment in their home shop. the only difference is the "chips produced" are metal instead of wood. the one advantage here, is if a mistake is made, metal can be "added" and the mistake repaired by welding then re-doing the item in question.
whereas i haven't found a "wood rod or wire" that could be used on any of my welding machines.

Ours does to, call and ask if they turn drums, never referred to it as grinding.... Could be the part of the country you are in for different terms used.

Years ago, long before I started driving, it was common to have a motorized grinding wheel that mounted on a fixture in a manner like a drum lathe tool bit does. The reason for using the grinding wheel was that hard spots in the drum could be ground smooth without ripping out the metal like a standard steel tool bit did. When carbide tool bits became commonplace, there was less need to grind the hard spots out, and since time equals money, and real machinists get real money, grinding drums went the way of the Dodo.

Same deal with arcing brake shoes. It's hard enough finding competent machinists, and if you do, they want to be paid. Besides that, people realized that asbestos dust if harmful to your health. Eventually, more parts suppliers started stocking oversize shoes that worked well enough without needing skilled labor to make them fit the drums. .030 and .060 oversize became commonplace. When I would do stock updates, I even found shoes in parts stores that were .090 oversize. Drums would be getting awful thin at that point.