Locksmithing and Security

Imagine, heaven forbid, a bent postal worker, e.g. working in your local sorting office, who sees an envelope with an address on it (surprise, surprise) and can see or feel a key inside. Pretty tempting eh? You might also want to check out this Channel 4 programme

If you’re sending keys through the post, you must disguise their outline. We always cut around the key into some corrugated cardboard and tape the key in the hole, and we obscure the key’s keyring hole. And we then wrap that in paper and tissue paper.

You’re probably lucky if you make the even more basic mistake (and another locksmith sending me a key did this!) of putting the key, on its own, in an ordinary envelope. Let’s see now: key = sharp & metal, envelope = fragile & paper ⇒ key leaving envelope somewhere on journey (and hopefully before our putative bent worker sees it).

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.

When you’ve moved into a new place and are contemplating the pile of keys you’ve acquired, put the ones that don’t seem to be for anything into a drawer somewhere (unlocked). But make sure that the keys that go in your pocket or purse are the complete set of front door keys. The most likely time to suffer a lockout is during the first two or three days of having moved in.

Apart from coming across intriguingly locked cupboards, mystery keys might operate locks from the inside. If you’ve got a rim lock with a key on the outside and a key on the inside, don’t assume that the outside key also fits the inside lock. If the outside cylinder was ever compromised and changed, its key will no longer operate the inside lock; and hopefully the inside key was kept.

If someone double locks the door as they leave, while you are still on the inside, you’ll be grateful you kept the inside key. You won’t have to yell to passers by from your window, throw them your key and keep your fingers crossed that they don’t just run off with it.

I had a couple of safes to open a little while back. One was an elderly Chubb and the other was a more recent Dudley. Both were key locks. Safes are divided roughly 60:40 in the UK between key locks and combination locks whereas in the States they’re nearly all combination locks. Of course, key locks are much more difficult for the safe engineer to open. Anyway, these two need different techniques so I started with the one that needed the venerable Hobbs pick. (I’ll come back to Mr Hobbs another day in another post.)

First you get as comfortable as you can. Other locksmiths poke fun at my collapsible chairs but hey. Then you get acquainted with the levers — seven in this case. You’re doing a couple of things here but it’s quite repetitious. You either get bored on unlucky days or you enter a Zen-like altered state on lucky days. This was a lucky day.

I wasn’t aware of it — that’s the point — but after five minutes there was almost nothing in my mind except a growing picture of my friends the levers. What I was also unaware of was that the lights had gone out; this was a basement of a delicatessen undergoing refurbishment and they’d cut the power to install some board or other and they’d told everyone but me.

So there I was in a gloomy corner, dressed in black (good for the image), forehead resting on a safe door, making no noise except for the occasional and pleasing click of a tumbler; and there was the electrics board that was about to be replaced, above my head. The electrician walked in pointing her torch high up at the board. I wouldn’t have heard her even if she’d been wearing wooden clogs.

I think we both screamed. I certainly lost all the levers.

Still, I don’t normally need meditation classes.

Many customers don’t realize that their rimlatch (their “Yale”) lock might be of the double-locking type.

If there’s a keyway in the inside handle, what’s it for? Well, first of all it might not work. If you had the outside cylinder (or barrel) changed at some point because of lost or otherwise compromized keys, chances are that you didn’t get the inside cylinder re-keyed at the same time, so it needs a different, probably lost, key.

Its purpose is twofold: to lock the bolt and to lock the inside handle/knob. I’ll come back to a more detailed explanation of the former in a moment.

Why would you lock the inside handle? Because if someone has broken into your property at the back, they would probably prefer to carry your plasma screen TV out of the front door. But if you’ve locked the handle they can’t.

Your rimlatch might still be double locking even if there’s no keyway in the inside handle. It’s quite often the case that you can lock the bolt and the inside handle/knob if you turn your key full circle in the opposite direction to the normal, unlocking direction.

Now, the main reason for this post if you’ve the latter variety of double-locking rimlatch, is to warn you that you might lock someone in one day. It goes like this: you never realized that the latch was double locking; you left as usual pulling the door shut behind you; you realized you’d forgotten your umbrella; you unlatch the door leaving your key in the lock as you grab your umbrella; then you pull the door shut again and turn the key. Now anyone left inside can’t get out. Even if they have their outside key they can’t unlock the inside handle. The only thing they can do is call to a hopefully honest passerby and pass them their key through the letter slot.

By the way, if your key takes three-quarters of a turn to open the door, rather than the more normal quarter turn, then it’s possibly a double-locking lock that’s had its double-locking disabled.

(In the UK, you may well have a mortice lever deadlock as well as a latch. Once that’s locked then your door has also been secured in both directions. For some reason mortice deadlocks never gained popularity in the States or in continental Europe, where break-ins are easier — although not necessarily more common — Brits seemingly being a villainous lot.)

What do we mean by locking the bolt? A latchbolt latches: you don’t need to use any key in order to make the door shut behind you. This happens because the latch is sprung and the closing face of the latchbolt is angled whereas the opening face of the latchbolt is flat. This convenience is also a security hazard because a burglar might be able to get something to push against the sloping face and unlatch the lock. So that’s why we might want to lock the latchbolt.

(If a lock bolt is unsprung and a key required both to shut it and to open it, it’s what we call a deadbolt — it’s not live, i.e. sprung.)

Some expensive locks — like an Ingersoll — automatically deadlock as they latch shut.