Locksmithing/Schlage top pins


I own several rental properties, all with Schlage locks.  About a year ago I purchased the 40-133 kit and have rekeyed about two dozen cylinders for both, my master and the tenant keys, using the follower method.  My question is about the top pins.  The kit contains top pin 1 (0-3) part 34-101, top pin 2 (4-6) part 34-102 and top pin 3 (7-9) part 34-103.   I always assumed that if you use a bottom pin in the 0-3 range you would then use #1 top pin, and so on.  I recently took a cylinder completely apart (just curious) and all the top pins were #1, even though a couple of the cuts were in the 4-6 range.  Was it same because of the master pins?  Can you please explain how to properly use the three top pins?  The kit also contains top T pin (F 506-451).  When do you use one or the other?


Bottom pins relate to the cuts on the key you want to operate the lock with.
Top pins relate to the size of the bottom pins in the same chamber.
Master pins are to allow a tenant key and a master key to both operate the lock and those relate to the difference of the cuts on both keys.

For every bottom pin you have, you'll use a top pin that is long enough to do its job but not too long where it fills the chamber to the point of being full which can cause the bottom pin not to move high enough to allow the key to enter.  This differs if you have a master pin in the chamber.  You have to account for those when choosing a top pin.

For the most part, the top pins that are included in the lock are okay to leave in place but if you notice the key being hard to insert or remove you may want to use a smaller top pin.

Master pins, likely listed as top pins in some kits, are for using when 2 or more keys of different cuts need to operate the lock.

To determine the master pin, write down your master key and change key as if you were adding the numbers together:

12345 Master
54321 change key
12321 bottom pins
42x24 master pins (x in this example means no master pin because the cuts on both keys are the same.)

Top pins would be determined by adding the 2 pins together and figuring out according to the chart which ones to use, again making sure you aren't filling the chambers full with too long top pins or they have nowhere to move when a key is inserted.

I hope this helps.



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I do not answer Safe or automotive questions. Period. I am knowledgeable in almost every area of Locksmithing. This includes locks, keys, lost keys, residential and commercial lockouts, rekeying, masterkeying, high security locks, access control, electric locks, security cameras and home safety. I have been running an online business since 2004 where I sell all types of lock and security hardware to everyone from apartment renters to business owners to the US government. Before that I started a locksmith service in 1999. I deal with many types of security equipment including high security safe locks, heavy duty padlocks, exit devices, biometric readers, electric strikes, magnetic locks, full surface hinges and I only sell what I personally stand behind 100%. The online business has given me a more in-depth look at the locksmithing industry, helping me to learn more about each and every product that I offer, as well as products I don't have but end up finding for customers to solve any issues they have with security or door hardware.

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