Decode

To measure the inside of a lock with specialist tools in order to obtain the bitting, allowing a key to be cut.

The term "decut" is not a standard, official term in the professional locksmith industry. However, it is a commonly used shorthand or informal term for the process of decoding a key's cuts or determining the bitting code.

In simple terms, "decut" refers to the crucial step of figuring out the exact pattern of grooves and ridges on a key.

This process is absolutely essential for creating a new, perfect working key, especially in situations where the original key is not available, is broken, or is simply too old and worn to be accurately copied directly on a standard duplication machine.

Determining the Bitting Code

Every working key has a unique sequence of numbers, known as the bitting code, that corresponds to the specific depths and positions of the cuts along the key blade. The goal of "decutting" is to translate the physical shape of the key (or the lock itself) into this numerical code.

Specialists use a few key methods to achieve this:

• Key Gauge: If a key is available but too worn to copy, a locksmith uses a precision measuring tool called a key gauge. This tool has numbered slots that allow the technician to measure the depth of each cut and record the precise code.
• Decoders (Lishi Tools): For automotive or specialized locks, technicians use sophisticated tools that are inserted into the lock. These tools allow them to manipulate the internal components (the pins or wafers) and "read" the corresponding cut depths, giving them the code without needing the original key.
• Code Retrieval: In the case of lost keys, the locksmith may access proprietary manufacturer databases using the vehicle's VIN (Vehicle Identification Number) to look up the original factory-assigned code.

Once the key has been "decut," meaning the code has been successfully determined, the locksmith can then use a high-precision code-cutting machine to create a brand-new key to the exact, original manufacturer specifications. This ensures the key works perfectly, unlike a copy of a worn key, which may cause issues in the lock over time.