Can you determine the number of pins from a key?

[mr_gray]

Hi everyone I'm new here and just getting into lockpicking as a hobby, but I couldn't find this question on the forum. Given a key, can you tell how many pins are in the lock it belongs to? I haven't had a real opportunity to go out an buy some master locks to practice on so I was just playing around with the front door of my apartment, which I believe is a medeco (it says 51S or 5IS on the face of the lock), and I was wondering if you could tell the number of pins based on the grooves in the key? Just curious. Thanks.

[yng_pick]

I'd recommend getting the practice lock;
Medeco are high security and quite difficult, your not likely to get anywhere starting with it. Plus- if it happens to get damaged while toying with it, can be pricey to fix/replace/gain access.

From looking at the key the valleys of the cuts will tell you how many pins the locks has.

For instance, this key has 5 valleys, and five pins

http://www.bumpmylock.com/images/M5.gif

this one has 4

http://www.bumpmylock.com/images/M1.gif

I just google imaged those, I no nothing of that site.

You can also place a pick in a lock, lift up on all pins, and draw the pick slowly towards you. Count the number of pins you hear resetting.

[mr_gray]

Awesome, thanks for the reply and the advice.

[globallockytoo]

From looking at the key the valleys of the cuts will tell you how many pins the locks has.

I am not bustin ya nuts, but a five pin key generally has more than 5 pins in it.

If it is heavily master keyed then there could be as many as 30 pins in each cylinder.

[nostromo]

mr gray, the keys' cuts will tell you how many pin wells there are. Assuming that you are, indeed, working on a pin tumbler lock, there will be one bottom and one top pin for each pin well. The manufacturer and model, as well as the circumstances, of the lock will give you a good idea if it's masterkeyed. A Small Format Interchangeable Core cylinder like Best or Falcon means 3 or more pins per well. If the lock is in a multiple occupant dwelling, especially with a large number of units, it will be masterkeyed.

[jwhou]

Sometimes if the key position closest to the bow is at the shallowest cut, a six pin key will be mistaken for a 5 pin key. I've noticed that the bitting on the key that the builder keyed my house to was often mistaken for a 5 pin key because the two pin positions closest to the bow where number 1 cuts. I also found that half the locks were missing pins and springs from the pin hole closest to the bow and that none of the cuts were deeper than number 5 (Kwikset has 6 levels of cuts). The locks were also supposed to come with three spool pins each but there was only one spool pin in six locks. I suspect that the builder not only keyed the locks to builder's keys hence no level cut deeper than five (presumably they reserved number 6 cuts on some of the builder's keys) but they were pocketing spools, pins and springs while keying the 6 pin locks with 5 pins each. Unless you have a selection of several random keys to look at, you have to make an informed guess based on the number of levels you see on the key, the key blank (KW10 works in both 6 pin and 5 pin locks) and the keyways of the locks themselves. The 5 pin Kwikset locks look like there's a square section of metal that hasn't been cut out because it hasn't, a cutout there would allow a 6 pin key to enter more deeply than a 5 pin key. From the key alone, you can make a good guess but it may be wrong.