The handle, key or the levers break( yes we have seen some very nasty lever and spring damage). I think that the customer is not properly informed about why the lock is so cheap. This occurs mainly at the big chain store level where no advice is offered to the customer about quality of lock or the price of replacement keys. For instance yesterday a customer brings in a M12H, which is a Union 2 lever key. This keys profile was totally different to the Unions profile and it cost her almost the price of the lock. Actually about US$ 50c cheaper duplicating the keys as compared to the price of the cheap lock.
We try, without success most times, to explain that buying the better lock will be cheaper in the long run because it will last longer and the key is cheaper too. There is a US$ 2 difference but cheaper they will go for.


