Impressioning locks is one of the basics of locksmithing. Possessing the ability to hand file a key to a pin or wafer lock is crucial to being an efficient and successful lock technician. Locks often have codes printed on them to cut a key by code, however this isn’t always the case. Even if the lock has a code, there are sometimes the wafers or pins have been changed. Situations like these require a locksmith to impression the lock. Depending on the level of skill and experience, some GM sidebar locks can even be impressioned using more advanced techniques. Proper locksmith tools are essential to this process.
Sevaral types of files are available and many of the variations come down to the particular style of a locksmith. A round key file is narrowed at the tip and gradually grows larger. The file remains completely round all the way through. Some technicians prefer to use the round file because of the surface area available on the file. Sometimes the file can clog due to the different types of metals filling the grooves which no longer provides an efficient filing surface.
Other locksmiths prefer a lock pile called a pippin file. This file has a side that is rounded side and one side that comes to a steep angled edge. The edge creates some versatility and can do things that the round file cannot do. With the angled side, many of the rounded places of the key can be cleaned up and made to look similar to a code cut key.
The last type of file we will discuss here is the warding file. This is a flat file that serves a variety of purposes. A popular use is sharpening or “knife edging” a key before impressioning. This technique is used by many locksmiths on pin style locks that require hand filed. This file can also be used to straighten some of the sharp peaks between spaces on a key.