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Locksmithing/Replacing Door Cylinders (mainly F-Series)


Hello! I learned a lot from reading some of your other answers while searching for my topic.  I moved into a house that has 3 door locks and 3 deadbolts.  The doors are F-Series and the deadbolts are B60 types.  From what I've read the B60s are Grade 1 and the F51s are Grade 2.

From looking at some YouTube videos, the re-pinning process looked easy so I decided to tackle it.  I also thought it would be a nice opportunity to key them alike.  The deadbolts were very easy.  I only had one problem where the screw went in crooked, but appeared to be screwing in.  When I locked it, the bolt stuck out and I needed to remove the deadbolt to get it to retract.  A nice lesson learned.

My first door knob was an adventure.  I wasn't careful when I pulled the cylinder out and I popped the cap off, springs and pins everywhere.  My kit had springs, top pins and caps, but they were different so when I used them to reassemble it, the lock would turn but I couldn't remove the key.  I assumed that the different parts made the pressure against the center of the cylinder too tight.  I did a temporary workaround by using the T-pins and cutting off part of the springs and got it working.  This worked fine until I was able to order the correct parts and assemble it properly.  The other two door knobs were re-keyed easily due to my second lesson.

Now my questions.  I'm happy with the deadbolts but not with the knobs.  The springy loose tops of the F-Series cylinders do not "feel" secure.  Even though they say it is Grade 2, I think it would be easy for someone to make a gadget that could push up the 1st & 5th pin to pop the cap off.  Is this a valid concern?  I was wondering if I could put a different cylinder in the F51 knob.  I'm not sure if such a cylinder exists because you need to compress the springy top to get the cylinder in and out of the knob.  If one exists, could you let me know?  Also, is it possible to replace a 5-pin cylinder with a 6-pin?  There are probably some size concerns to deal with.  BTW, I've found replacement T top pins, springs and the F caps, but haven't seen any replacement F-cylinders for sale.  Is there a reason for the unavailability?  Sorry for so many questions.  Thanks in advance.

Hello Chuck,

Schlage F series may be marketed as Grade 2 but my experience tells me they don't conform to the standards set forth by the companies that test and grade locks. Grade 2 locks must withstand 400,000 cycles and something around 60 foot pounds of force, not to mention the amount of torque they are required to withstand (I can't remember the number but it's a lot).

The spring caps are a major issue and bypassing them is generally simple. There is no way to fix this issue on the cylinders that are included with the locks.

There are no replacement cylinders available for these locks other than exact replacements.

The deadbolts should be adequate enough for most applications. Make sure you use a thicker strike plate and at least two 3" long #8 or #10 wood screws.

I generally suggest using a passage knob or lever and a deadbolt on each door. If you want the extra protection a second lock provides, use something other than a Schlage F series. Arrow, Falcon or even some off-brand locks would be better than those.



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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.

Please don't submit any automotive or safe questions as these aren't areas that I can help in.


I have been Locksmithing since 1999 and own my own Locksmithing business. I have many years of hands-on experience through the many services I have performed for my customers. I've run my business the way I wanted, treating everyone as I would like to be treated and knowing that any customer could be my last if I didn't perform my locksmithing duties as I had promised.

I have a diploma in Masterkeying, Advanced Locksmithing & Locksmithing from Foley-Belsaw.

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