size of top pin?

[patrick_lpk]

Hi,

sorry if I'm asking a dummy question (sometimes it's better to stay quiet and look stupid than open your mouth to prove it!)

Are the upper pins always the same size? If so, could we push both pins all the way up to have a direct reading of the length of the bottom pin?

I've read about weighting the pins to decode them, but measuring them seems easier no?

[Olson Burry]

The driver pins (top) are usually all the same length but could be a mix of steel, brass and different types of security pins.

The problem with pushing them all up that far to get a reading (apart from creating a tool to accurately measure the distance) would be the spring at the top. They may compress differently, the ends may get wodged in to the side trapping the driver, they could tangle and never spring out again, anything could happen.

There are methods of opening a lock in a similar way to your description however it is advanced and could result in breaking the lock in the long run anyway so is not recommended.

[sfi72]

Most of the ASSA locks that I have taken apart had different size driver pins, but other than that I have always seen them the same size in each lock.

[cryptocat]

Hi,

sorry if I'm asking a dummy question (sometimes it's better to stay quiet and look stupid than open your mouth to prove it!)

Are the upper pins always the same size? If so, could we push both pins all the way up to have a direct reading of the length of the bottom pin?

I've read about weighting the pins to decode them, but measuring them seems easier no?

The uppers are not always the same size, especially if there is master keying involved.

I just measured one of my practice cores. The top pins are

• 4.89mm
• 4.91mm
• 4.89mm
• 4.89mm
• 4.90mm
• 4.88mm

I've also crushed one of the springs and bent another, so I know they're not pushing evenly. And from the "well, duh" department, the key and bottom pins add up to 12.85 +/- 0.03mm

[patrick_lpk]

There are methods of opening a lock in a similar way to your description however it is advanced and could result in breaking the lock in the long run anyway so is not recommended.

I presume that you are talking about comb pick that is pushing both pins out of the tumbler.

[chev49]

I'm with Olson about the driver/security pins. I think you mean same length, not same size (as in diameter).

[patrick_lpk]

I've also crushed one of the springs and bent another, so I know they're not pushing evenly.

the destructive part of this method seems that's definitely not a good solution.


I'm reading some patents of some creative ways that were found to decode a lock. I'm amazed.
But coming from an electronic engineering background, I'm wondering if I could apply some new technologies to improve the same concepts...

Don't ask me a solution to your problem, but show me a solution and I'll find you a problem to use it.

[datagram]

To OP,

Long story short: in low security locks, yes. In medium-high security locks it varies. Most have what are known as "balanced drivers", which means that the length of all pin stacks is the same; the top pin size is dependent on the size of the bottom pin. This helps to prevent comb picking (as mentioned above) as well as various forms of decoding.

I have a kit of Schlage security pins used for balanced pin stacks. If you'd like to see a picture just let me know.

dg

[cryptocat]

I've also crushed one of the springs and bent another, so I know they're not pushing evenly.

the destructive part of this method seems that's definitely not a good solution.

Wasn't intending to be destructive or using a technique I knew to be unsafe. One of them I was mashing way too hard on the pin with way too tall of a pick. The other, I was re-pinning, took the driver out but not the spring, and it got caught... you know how that goes.

As for decoding, wouldn't it be easier to just pick the lock open, turn it about 20 degrees and measure the height of the bottom pins as they're pressed up against the cylinder?

[Squelchtone]

As the others have said, ASSA has balanced pin stacks, Medeco does as well, and other high end brands also.

here is an example:



In the above pic they are presented with the shearline on center. As you suspect they are designed to stop decoding of bottom pin lengths, but as an added bonus, they help keep the springs from compressing too much, and they add to a smooth feel when the user inserts or removes the key, because all the pins travel the same distance and all require the same amount of force for the key to lift them. These ASSA pins are also spooled, and are easily trapped in counter-milling inside the pin chambers of the plug.

Cheers,
Squelchtone

[patrick_lpk]

As for decoding, wouldn't it be easier to just pick the lock open, turn it about 20 degrees and measure the height of the bottom pins as they're pressed up against the cylinder?

You got a point there

[freakparade3]

Datagram is 100% correct. In a properly pinned lock you will have different lengths of driver pins to balance out the stack.

[patrick_lpk]

Datagram is 100% correct. In a properly pinned lock you will have different lengths of driver pins to balance out the stack.

That would make sense. I was just worried about this weakness as in most of the books I've read, they were saying that the driver pin were all the same size.

My skills are not good enough yet to compete with medium or high security locks. We'll see in a few months.

Thanks for the info, I'm learning more in this forum in a few days than in a lot of other source.