A guide to Best Bitting practices?

[FredW]

I'm planning on rekeying a bunch of cylinder locks to a single new key.

I'd like to make them reasonably challenging for anyone trying to pick them, while still being real functional locks and not some crazy challenge lock that may open if you hold it at just the right angle and will wear the key out on the second use because of ten pound springs.

I don't have a pre-cut key and I'm not going to master key, so all the lock info I've found in several hours searching on the web is useless ("insert the new pre-cut key and drop in the numbered pins shown on the card").

I know how to file a key. What I'm looking for is general rules on what a "good" bitting pattern for a real key should look like.

I'm not planning on using security pins (other than the standard pins for this lock type are threaded), so I'm well aware that a decent picker can get in fairly easily. But even using standard pins, there is good and bad bitting, and I'd prefer to have good.

Thanks for any and all suggestions!

[GWiens2001]

To keep it simple, look up the MACS for the specific lock. That is Maximum Adjacent Cut Specification. That will tell you how different you can make the cuts next to each other on the key. It is affected mostly by pin shape and angle of the cuts (that varies by the cutter).

[FredW]

Unfortunately I have been unable to find MACS info for Sager locks. The table you pointed me to in the other post doesn't seem to include that information, or if it does it is under another term and I'm not recognizing it.

[6275LA]

Avoid descending cuts, flat cuts, and too much repetition of the same pin length. Alternating high/low cuts that result in pointy cuts to lift a short pin will wear faster than more standard cuts, but will give years of service in household locks where the key is not used a hundred times a day. Other than that, you decide. Maybe a Google image search for Sager key will give you enough images to sort it out.

I have a couple of locks pinned high/low like that and they have worked well for years, but they get used only about twice a week for 10 months of the year. One is a Sargent, with the key cut on a very thin Cole National blank, and still works like new. Should it quit working, I have a backup entry solution all ready.

[mastersmith]

It sounds like you want to learn a little. Take a look at this list of resources https://lsamichigan.org/links.html . For general keying information go to Corbin / Russwin, resource library, cylinders / keying. There is a wealth of info there. Specific Sager info will be difficult to find because they went away before the computer age grabbed hold of us. They are listed in the HPC space and depth directory. Good luck.

[GWiens2001]

I will add that the cutter listed for Sager is a HPC CW-90MC, which is the same as is used for Best SFIC locks. So you will likely be able to do most cuts next to each other. I'd still avoid going full high and full low next to each other. But most non-extreme depth changes should be fine.

Gordon

[FredW]

Thanks for the reply. Looking at the table on bitbucket from the link you gave above, I see two Sager keyings: an 1804 and a 1804 1/4. These seem to be very similar except for the TFC and BCC dimensions, which increment by .156 for the 1804 and by .200 for the 1804 1/4.

However, neither of these match the cylinders I have in hand.

After some digging around, I by accident came across "Schlage Primus/Primus XP/Everest Primus" which appears to be identical (or very nearly identical) to the dimensions I have on my cylinders. In particular, TFC and BCC appear to match the cylinders I have, and the cut depths are the same as the Sager keyings given in the table. I'm going to have to dig out a better micrometer and go use the microscope to be sure of the dimensions, but except for the keyway shape (which is key pattern SA1 for these cores), all else seems to match within at least a few thousandths.

I don't have any specifications on HPC CW-90MC cutter and am unclear on where to find that info. I'm guessing the "90" might refer to it cutting a 90 degree included angle. The spec for the Schlage key included angle is 100 degrees, which of course a 90 degree cutter will cut with no problems.

[GWiens2001]

Link to the HPC CW-90MC. The pic has the specifications.

Gordon