by MacGyver101 » 29 May 2011 7:19
When people talk about "tolerance" in the context of locks, they're usually talking about manufacturing tolerances, rather than "picking tolerances" (although the two are related).
Mass-produced, low-cost locks are usually manufactured with lower quality tolerances than higher-end locks -- and a lock made with lower tolerances is probably going to be easier to pick. (For example, the pin chambers may not be aligned as well, or they may not be cut quite the same... this would make it easier to find binding pins, etc..)
In contrast, locks made to higher standards (or "higher tolerances", if you will) are more uniform in their construction, and the parts fit together better. This provides less feedback while picking, and makes it harder.
There was a good thread posted a year or two ago on the factors that make a lock harder/easier to pick; if you search for it, you'll find that many of the more significant factors are related to manufacturing.
Hope that helps to clarify things a bit?