How locksmiths make new keys to a car

Ever wonder how a locksmith determines the proper cuts for a replacement car key if you have lost all your keys? There are several ways, but each has its advantages and disadvantages.

  • By Vin number. Many auto manufacturers will record the “Key Code” when they sell the new car. The record this information in a database and attach it to the vin number of the car. A locksmith with proper credentials can run the vin number through the database and get the key code. The key code is then put into software that will show the proper cuts. The down side to doing it this way is that the locksmith must buy this code and they will undoubtedly pass that cost along to you. Some of these codes can be $50 or more. In addition, sometimes an ignition or door lock will have been replaced and the new one does not match the the original key code attached to the vin number. When this happens, it means the locksmith wasted money buying a code that does not work. Also, the companies only keep the key codes for a limited amount of years. Sometimes the codes simply are not available. To get these codes, the locksmith must belong to NASTF, an organization developed to secure these key codes. Without a NASTF ID, the locksmith is unable to buy key codes. Joining NASTF is costly and takes a significant amount of time and effort. They complete a background check to make sure the locksmith has proper licensing, insurance and criminal history check. They also have an ongoing audit process that prevents abuse of the ability to get key codes. Many less professional locksmiths will not belong to NASTF and will be unable to buy codes at all.

  • By decoding a door lock. Most cars on the road today use a single key that operates the door, trunk and ignition. Often, none of the locks have all the positions filled. As an example, a Ford has 8 positions. The door will often have cuts 2 through 7. The ignition will have all 8. The door lock will be picked and the locksmith will obtain the first 6 cuts from the door. Since most ignition locks are not pickable, the locksmith will then use a software “fill program” to determine the remaining two cuts. These fill programs have all known key codes and are able to figure out the missing cuts by sorting through all the mathematical probabilities. This is an inexpensive way to make a key and it gets around the cost of buying a key code. Most professional locksmiths will prefer this method. The problem with this method is they tools are difficult to use and require extensive experience. In addition, there are times when on a 10 cut lock, the locksmith will be missing 3 cuts after decoding a door lock. The mathematical probabilities be come larger the more missing cuts there are. If the fill program gives back a list of 15 possible keys, it isn’t practical or cost effective to cut keys until you find the proper key.

  • By finding a key code stamped on an existing lock. Many cars stamp the key codes on a lock or ignition cylinder. On some vehicles this is the easiest way to obtain a key code. As an example, most late model Toyotas will have the code on a passenger door lock. This is often a matter of removing a single screw and removing the lock to read the key code. The down side of this method is that many car manufactures make it very difficult to remove the locks. Some require the door panels to be removed. Some ignition locks must be turned to the on position in order to remove them. This can be very difficult at times when there are no remaining keys.

  • Impressioning the lock. Some locks on older cars can be Impressioned. This is a process of inserting a blank key in the lock, turning it to bind the pins, and moving it up and down to force the pins to mark the key. The marks are filed down until the stop marking. This is done for each space on the key. Eventually the key will work. This process takes a great deal of practice and patience. It is not done often.

Geff Greenwood