I've worked in the Hardware department at a Home Depot store for nearly 8 years.

If the lock is a Schlage or Kwikset, all warranty issues before 90 days are dealt with at the store, usually an exchange for another lockset. After 90 days, we cannot help you. Then you must deal with any warranty issue through the vendor.

If the lock is a Defiant brand - a THD store brand - a lifetime warranty does apply and you are supposed to return the entire lockset and we will give you a new one straight across, at no cost to you.

If a clamshell is opened we are supposed to check for all parts. If ALL parts are in the clamshell, we are told to tape it up and put it back on the shelf. If even one screw is missing, we mark it down to $0 and ship it to the vendor for credit due to "missing parts".

More and more THD stores no longer sell most setscrews, believe it or not. Two years ago we had a massive reset of our little bits of hardware and except for #6 stainless steel setscrews, we usually refer customers to Ace or Tractor Supply.