Lock Engineering

Firstly, make designs of a door lock

Get through what the customer want door lock to be

 As you see, the door lock comes in grades, from low-security to high-security. Generally, people make a low-security lock from cheaper materials. So its parts can be mass-produced. A company that manufactures low-security locks can have two (or three) available models. They will keep in stock the parts needed to customise them. The lock manufacturer is generally as an original equipment manufacturer. They make the parts for their door locks as well as the final products. This manufacturer may keep only the most basic and common parts in stock. Most of its orders require custom design.

 In fact, the process begins with the manufacturer assessing the customer specifications. For example, the customer orders a door lock to fit a certain size door. He wants he can open it with a master key. Then, the manufacturer comes up with the best design for that customer needs. The customer may have purchased locks in the past from one company. Now, he wants more identical locks from a different manufacturer. This company will promise to make them more economically. After that, the manufacturer examines the customer’s original locks. Finally, they go through what is known as a reverse engineering process.


Design team starts their work with door lock

The design team figures out from the existing lock and how to make their product match it. In many instances, the first lock company has patented aspects of its lock construction. Therefore, the second manufacturer may not duplicate it. The designers “design around” the first company product. They produce a door lock that will match the customer’s originals and serve the same purpose. However, they will use different mechanisms.

In most cases, both medium and high security locks go through this design stage. It makes the production of locks a time-consuming process. A reputable manufacturer will not make low security locks. They may take from eight to 12 weeks to produce locks for an order. It is from the time they receive specifications to when they pack and ship the product.


The key

For the standard five-tumbler key door lock, people make the key first. The manufacturer buys key blanks. Next, they cuts the ridges or combinations, in each key. Each key has five bumps on it that the manufacturer cut to different levels. Accordingly, these levels are designated by numbers. Namely, a low cut is one, next up is two, then three. Generally, there are four levels only. However, some manufacturers may use as many as seven.

The five-tumbler key lock with four levels in the key yields. It brings four to the fifth power or 1024, different possible combinations of ridges in the key. The five ridges are listed by the height of each level. The key with the combination 12341: people cut with the first ridge at level one, the second at two, the next at three and so on. The manufacturer chooses the combinations from a random list. Next, they cut each key differently.

Picture 2: Key of a door lock is extremely important part

Internal mechanisms

Next part of the process is the internal mechanisms. The manufacturer has designed to fit this particular lock order. Additionally, the machinery makes them may have to be re-tooled or reset. People must produce the tiny interior parts, specifically the pins to exceedingly fine tolerances. Therefore, the machinists may make a trial run before starting a big job. After that, the machines may be re-set as necessary.

Actually, the machining of small brass parts will take many steps. You know, they may be cast, then grooved, ridged, jeweled and polished. Precision tools will handle these jobs. They cut the metal to within tolerances of plus or minus 0.001 of an inch.


Other parts of a door lock

The manufacturer makes the other parts of the door lock as well. The cylinder or plug that the key fits into; guard plates, washers, the bolt or cam, and the casing. The manufacturer make them according to design specifications. The number of parts varies with the design of the door lock. However, even a small and relatively simple lock may have thirty separate parts. Some parts require multiple toolings. The process of making the door lock components can take several weeks.

Assembly of a complete door lock

When all the parts are ready, people will assemble the door lock by hand. The workers sit at well-lit tables with a kit of the pieces of the lock in a bin. The key is on a stand in front of them. Moreover, an professional worker can tell the combination of the key just by looking at it. First, the worker fills the plug or cylinder of the lock with the pins. They correspond to the combination of the key.

Picture 3: Cross section of a typical door lock

Then, the worker inserts a tiny spring and the lock pin. They use a small tool called an assembly pick to hold the small parts. The assembly pick has a small screwdriver on one end and a point on the other. The worker uses it to prod the delicate parts in where they belong. Next, the plug is filled according to the key combination. The worker will snap or screw together the other parts around the lock. Although this is skilled work, it takes no special training. These workers are not locksmiths.

When a door lock is fully assembled, the worker will check it with the key to make sure it works. It may pass to a quality control station at this point. Finally, the workers package the completed door locks and box them for shipment.