Common Problems with Duplicate Keys and How to Avoid Them

Getting a spare key sounds simple, but it can quickly turn into a problem if the duplicate does not work correctly. Many people face difficulties after key cutting, especially when the new copy either fails to turn in the lock or only works after a struggle.

This article explains the common problems caused by poorly cut keys, how to spot a bad copy, and steps you can take to avoid these issues in the future.

Whether you're duplicating a house key, car key or office key, it pays to get it done properly.

Why Some Duplicate Keys Just Don’t Work Properly

Even though a key might look the same, tiny differences in the shape or size can stop it from working as it should. These mistakes often happen during the cutting process and may lead to big problems later on.

Below are some of the most common reasons why duplicate keys do not work as expected:

Worn Original Key

If the key you use for duplication is already worn down, the copy will also have the same flaws. A key that has been used for years may not have sharp, clear edges anymore. That makes it harder to copy it exactly.

Cheap Cutting Machines

Low-quality machines often fail to match the original key’s shape accurately. The grooves and notches on the duplicate may be too shallow or deep, even by a small amount, causing the key to jam or not turn at all.

Untrained Staff

Key cutting might look easy, but it takes skill. If the person cutting your key is not properly trained, there is a much higher chance of making mistakes. This is common in places that offer key cutting as a side service.

Poor-Quality Key Blanks

The blank key must be strong and match the type used in your lock. Using poor-quality blanks made of soft metals can lead to a weak copy that bends, breaks, or wears out quickly.

How to Tell If a Key Has Been Poorly Cut

After having a key copied, it is a good idea to test it straight away. But even if it seems to work once, you should still check it closely for signs of bad cutting. Look closely at the edge of the duplicate key. The cuts should be smooth, clean and match the original key’s shape exactly.

If the cuts look jagged or uneven, the key may not work well over time. If you insert the key and it sticks or needs wiggling to turn, that is usually a bad sign. A good key should slide in easily and turn with little effort. Forcing it could damage your lock.

Another thing to check is how the key feels. A poorly cut key might feel rough or too light. This could mean a weak or low-quality blank was used, which is likely to wear out faster than it should. Also, check if the key leaves metal shavings behind when you use it. That could mean the metal is too soft or the cut was not clean.

Over time, this can damage the inside of your lock and lead to more serious problems. Compare the original and the duplicate side by side. If you notice that the ridges and valleys on the key do not match up perfectly, it’s a clear sign the copy was not cut well. This difference is sometimes hard to spot without looking very closely.

Why It Pays to Use a Reputable Key Cutting Service

Using a trusted key cutting service helps avoid all of the issues listed above. These services usually invest in modern machines and trained staff, meaning better results every time. A reputable service will also check your original key for signs of wear and tell you if it is a poor choice for copying. They may even suggest cutting a new original from the lock if the key is too damaged.

Good key cutting providers use high-quality key blanks that last longer and work better. They also test each duplicate to make sure it functions smoothly in your lock before you take it home. While it might cost a little more than a basic cutting station in a supermarket or shop, paying for proper service saves time and hassle in the long run. A key that fails at the wrong time can cost far more in lock repairs or locksmith visits.

Some professional services also keep a digital record of your key’s pattern. If you need another copy in the future, they can reproduce it more accurately without needing the original again. This adds an extra level of convenience and security. Many trusted locksmiths are also aware of lock brands, key systems and the latest tools in the trade. This knowledge allows them to cut keys for more complex locks, such as high-security systems, which standard shops may not handle properly.

In addition, reputable services usually offer some form of guarantee. If the key does not work, they will often cut it again or fix the issue at no extra cost. This kind of service is less likely with cheaper or quick key cutting stalls. When you use a proper service, you are also more likely to receive advice about care and maintenance. For example, you might be told to avoid exposing the key to moisture or force. These tips can help extend the life of both the key and the lock.

Steps You Can Take to Avoid Key Duplication Issues

While it is the cutter’s job to produce a working copy, there are steps you can take to help avoid problems. Taking the right precautions means your new key is more likely to work well the first time.

By following a few smart practices, you can save time, money and avoid the stress of dealing with a faulty key when you need it most.

Start with a Good Original

Always choose the newest and sharpest version of your key for copying. If you only have a worn key left, consider having a locksmith cut a new original from the lock instead of making a copy of the worn one. It may also help to avoid copying a copy. Each time a copy is made from another duplicate, small errors can add up. This process is known as generational loss, and it leads to keys that slowly stop working over time.

Use Trusted Services

Do a bit of research before choosing where to get your key cut. Look for reviews, ask for advice, or use a place that specialises in key cutting, not just a shop that offers it on the side. If you are unsure, ask the cutter what type of key blank they are using and what machine will be used. A professional service will not hesitate to explain their process or offer peace of mind.

Test the New Key Straight Away

As soon as the key is cut, test it in the lock before leaving the shop. If something does not feel right, mention it right away. A good cutter should be willing to recut the key until it works properly. Try turning the key in both directions, locking and unlocking. Listen for unusual sounds and feel for resistance. If the key is catching or slipping, it may be a sign that something is off.