Locksmithing and Security

Some keys can be copied by anyone with a key cutting machine and some can’t. Those that can’t be (or shouldn’t be) copied are called restricted or protected key systems.

If you have to give keys out to friends or relatives or builders, or to nannies, au pairs or dog walkers, it’s nice to know that when those keys come back to you they are very unlikely to have been copied.

The downside is that when you do finally want another copy for yourself, it will be time consuming and expensive to get it. It may not even be possible. Restricted key systems are frequently specific to a particular locksmith, and if that locksmith has gone out of business getting copies is going to be from difficult to impossible.

If you are having a restricted key system fitted, make sure that you are told where key blanks can be got from if the locksmith, heaven forbid, goes belly-up.

If you are moving into a place, have a good look at the keys. If they are stamped with a locksmith’s name or with a longish number¹ they may well be restricted — ask, or try ringing the number and enquiring about getting key copies.

It’s much easier to come up with restricted key systems for pin tumbler cylinder locks than for lever locks. It is therefore your cylinder lock (the “Yale”) that is the more likely to be restricted. It is, however, possible to find a restricted key system lever lock (the “Chubb”); look at the stem of the key; if it isn’t cylindrical, it might be restricted.

¹ 1, 2 or 3 digit numbers stamped on a key don’t count. They are used to distinguish regular key blanks: 1A is a Yale 5-pin, 453 is a Profit blank, etc.