About a week ago, my husband and I bought 336 antique and old padlocks locks and some keys. About 100 of the padlocks are matched with keys. I am still in the process of sorting them, and trying to match keys to locks. My husband and I collect anything that we like-from glass to padlocks. But we don't know a lot about padlocks. We both love learning about things we've bought and after 40 years of collecting, we are happy to jump right in and learn about padlocks. But while I am sorting through this huge number of padlocks, I have some questions. I was happy to find this site, and I am using it to figure out what types of padlocks we have, and about the companies, value and keys. Today, I am most interested in keys. I am sorting the keys into shapes and thicknesses, brands, and things like that.
There are many flat steel keys, that seem solid, but very cheaply made. As much quality that went into the padlocks, I can't help wondering why the keys were so inexpensively made?
As I try to match a key to a padlock, am I going to hurt anything if a key fits all the way into the lock, but isn't a match? My husband says probably not, because people use the wrongs keys often.
We have some of the Scandinavian style padlocks, with large holes for keys. Will they all take a thick-shafted key or do some have other shape of keys?
We have Yale padlocks, plus padlocks that were made by Yale with different names, such as Terror. Did anyone ever do odds of any Yale key fitting any Yale lock?

I have matched 8 locks and keys since we brought the padlocks home and I can't tell you how satisfying it is when a padlock clicks open :) I'm sure we'll keep a few, but we'll sell most of these on eBay so we can buy other things we like. I'll be visiting this site often as I have time. If anyone has advice or can answer my questions, thanks!