Locksmith Charley

This page contains an explanation of the differences between "Ordinary" security locks and High Security locks and also explains the some of the differences in various grades of locks.  

In residential or commercial door lock applications there are 2 distinct types of locks - ordinary security and high security. Ordinary security locks most often can be readily picked open or very easily compromised by drilling. While it is true that ordinary security locks may be made more pick resistant by insertion of "mushroom" or "spool" top pins (or drivers) there is still absolutely no way to make them more drill resistant.  

There are 3 grades of locks - they are:
      Grade 1 - commercial - industrial
      Grade 2 - heavy duty residential / light duty commercial
      Grade 3 - residential / consumer expendable (ie "throw-away" locks)

Most residences have ordinary security locks such as Kwikset®, Weiser®, Weslock®, Dexter®, EZ-Set®, etc. 
Even such honored brands as Schlage®, Corbin®, Russwin®, Baldwin®, and others are usually equipped with "ordinary security" cylinders - even in their grade 2 and grade 1 offerings.  

High security cylinders are made to be "virtually" pick-proof and usually have hardened steel inserts in them to help prevent physical attack by drilling. There are a variety of types of high security cylinders made by several different companies. Some of the better known ones are Assa Twin®, Medeco®, and Schlage Primus®. 

High security cylinders usually cost in the $50.00 - 75.00 range and keys are usually $8.00 or more. 

The various features of these locks and keys follow.

ASSA TWIN 

Assa Twin® - as you can see by the picture above the Assa Twin key has some cuts milled into the side of the blade of the key. Inside the locks there is a set of pins called sidebar pins that interact with those millings. When the sidebar pins are all raised to match the unique sidebar within the lock the sidebar will be able to enter the plug. If all of the "regular" cuts on the key are correct as well then the plug will be able to turn. If either the sidebar cuts are wrong or the "regular" cuts are wrong then the cylinder will not turn. Assa's website (http://www.assalock.com/products.htm) says "ASSA locks employ a patented dual locking mechanism that renders the lock virtually pick proof." and personally I believe them.  My company has been assigned a unique sidebar for this region so if you want high security Assa Twin cylinders I can guarantee no one in the area other than Locksmith Charley will be able to duplicate them. What this means to you is that if you give an employee, housekeeper, babysitter, etc. an Assa Twin key and they return it to you that they have NOT gotten it duplicated. Only customers whose signatures are on the card kept on file in my shop can order duplicate keys and only after signing a restricted key order form. 

MEDECO

The Medeco lock also incorporates a sidebar inside the cylinder, but there are no special cuts on the side of the key like Assa Twin and Schlage Primus. Instead Medeco uses unique chisel shaped pins with a slot milled into the side of them. The pins have to be rotated to the correct angle as well as being raised to the correct height in order for the cylinder to operate. In the case of this key the cuts are R-L-L-C-C-C. 

SCHLAGE PRIMUS

Schlage Primus is similar to Assa Twin but there are a few differences. But again, the "regular" cuts have to be correct AND the sidebar cuts have to be correct for the cylinder to operate.

Anyone with any questions about High Security locks or any other aspect of locks, keys, security, etc is encouraged to e-mail me at mailto:charley@LocksmithCharley.com