Photo by Matt Blaze
Serrated pins are very different from their security pin counterparts. Serrated pins come in both driver and key pin varieties – the serrated key pins only serving the purpose to trap an over-lifted pin above the shear line, especially when combined with a serrated driver pin. The purpose of a serrated pin is to prevent the natural sliding of the pin across the shear line that is observed as a result of the binding effect. Rather, when a serrated pin binds, each serration acts as a mini ridge that gets trapped at the shear line. When you’re not accustomed to them, they can be quite unsettling because they give you the feeling that a pin is set even though it is not. When lifting a serrated pin you will feel a similar click to that which you experience when setting a standard pin. This can lead you to believe that you have already set a pin and move on. Even more frustrating is that the rotation of the plug when setting into the ridge of a serrated pin can transfer the binding effect to another pin stack in the lock. If you believe the serrated pin to be set and move on to the next binding pin, no only will you be picking in vain for some time, when you discover the serrated pin and try and set it correctly, you will often reset any pin stack that you have set after it.
It’s not all bad, however. Serrated pins can actually be quite easy if you can recognize them, or know to expect them. Some locks, such as American brand locks, are known to utilize serrated pins. Knowing this can help you to be better prepared when you encounter a serrated pin. Expecting a serrated pin will make you less trusting of the telling click and slight rotation of the plug common to pin setting. Once a pin is set, applying additional lifting force while easing off the tension will give you a quick indicator of a serrated pin. If you feel the pin begin to grind as the ridges of the pin cross the shear line, you will have a solid reason to believe you are dealing with a serrated pin. Of course, it is easy to over-set either a standard pin or a serrated pin while performing this test. Practice will allow you to learn to detect and overcome serrated pins.
Going back to your practice lock, re-pin the lock to include a serrated driver pin. Repeat the earlier exercise, this time paying special attention to the serrated pin. Familiarize yourself with the feel of the gently grinding while the serrated pin crosses the shear line. Once you feel comfortable with your ability to recognize and deal with one serrated pin, try adding more – one at a time – until you can successfully pick your lock with all serrated driver pins. Then try the exercise again with a different lock.
Full credit to: lockpickernetwork.wikidot.com