With passion since 1963
The address for hardware, locks and keys in Alkmaar.

The address for hardware, locks and keys in Alkmaar.

Known since 1963 for our old-fashioned good service.

Known since 1963 for our old-fashioned good service.

The Postma and Postma store has been a household name in Alkmaar since 1963.

We have a range of almost 15,000 items in the field of keys, locks and hardware. Of course in combination with good old-fashioned service. We also offer locksmith service at home. Whether it concerns securing an entire home or opening a door; We are ready for you.

Postma en Postma
Frequently Asked Questions
Which cylinder lock do I need?

An SKG 3*** cylinder lock is the safest because this cylinder is equipped with core pulling protection. If the security fittings on your exterior door are equipped with core pulling protection, an SKG 2** cylinder will suffice. You can recognize the core pull protection in the door fittings by the rotating disc in front of the keyhole. If your front or back door fittings do not have core pulling protection, you can easily solve this by installing an SKG 3*** cylinder. In this way, the lock complies with current security standards to significantly reduce the risk of burglary.

What is a knob cylinder?

A knob cylinder is actually the same as a normal cylinder, except that the cylinder has a knob on one side instead of a keyhole. This way you can always easily lock or open your door without needing a key. Knob cylinders are therefore often used in emergency and escape doors. It is a simple solution to ensure that a door meets the requirements of the fire brigade.

You can also never accidentally leave a key on the inside, which means you can no longer operate the cylinder from the outside. According to the requirements of the PKVW (Police Quality Mark for Safe Living), a knob cylinder may not be used in a facade element with non-SKG-approved glass. Otherwise it will be too easy to break a window and open the door. In practice, modern HR glass is not often smashed compared to the single glass of the past, but it is still something to take into account.

Why should I buy a mechanical cylinder lock?

A mechanical lock offers many advantages over an electronic cylinder lock. A mechanical cylinder lock is cheaper, more reliable, durable and easier to install. There is also another important advantage. A cylinder lock has an expected lifespan of 200,000 operations. We assume that good maintenance is required, so that you occasionally spray the cylinder lock with lock spray. A number of 100,000 services are even guaranteed. An electronic lock is almost always defective. And the lifespan is much shorter, because on average a mechanical cylinder lock lasts two to three times longer than an electronic lock.

If an electronic lock initially seems five times more expensive, in practice it is simply ten to fifteen times as much. An electronic lock always breaks at the most unexpected and inconvenient moments. And then it's double bad luck, because with a piece of electronic lock you can no longer enter your home or business premises. In our opinion, the advantages of an electronic lock do not outweigh the disadvantages. So choose a mechanical cylinder lock; fast, affordable and reliable.

What is an emergency and danger cylinder?

An emergency and danger function is also called a hotel or panic function. This is not entirely correct, because it is called an emergency and hazard function, abbreviated N+G. This is a special coupling in the middle of the cylinder that ensures that the cylinder can also be operated when there is a key on the other side.

Normally this is only possible if the key is upright. Emergency and hazard function is often applied to the front door, especially in apartments with only one entrance. This is also very practical for people in need of care. If someone has left a key on the inside, you can always open the door with a key on the outside.

What is an SKG-certified cylinder lock?

An SKG 2 star or SKG 3 star certified cylinder lock is equipped with a key that cannot be easily copied. You can only have the keys counterfeited upon presentation of the certificate. The advantage of this is that you can safely give your key to your employees or to your neighbors or your daughter's boyfriend. They cannot have the key counterfeited without your knowledge.

We always work with small systems, so that the key cannot be copied after a few years. This is the case with major brands such as Nemef and Lips.

What is a locking plan?

In addition to keyed alike cylinder locks, we can also help you with locking plans outside the webshop. These are systems where certain keys can only operate the designated cylinder locks and another key fits everything: the master key.

You can set up such a locking plan exactly as you want. If you contact us by email or telephone, we will advise you on drawing up a closing plan together. Of course, you can always drop by our store in Alkmaar.

How do I measure a cylinder lock?

The size of a cylinder is expressed in millimeters. It is actually the length of the cylinder divided into two with the screw hole in the middle in steps of five millimeters with a minimum length of 30/30: or 60 millimeters. If the door is four centimeters, the cylinder is automatically 60 millimeters long, so the cylinder protrudes ten millimeters on both sides. This is for the fitting that is still on the door.

From the basic size of 30/30, the cylinder can always be five millimeters longer on one side. A commonly sold size, for example, is 30/45, this size is used on new-build doors that are thickened by fifteen millimeters on one side.

A detailed description of how to measure a cylinder lock is available online. And you still can't figure it out? Then please contact us. We like to help you.

Lost key. What now?

Losing your key or bunch of keys is not without risk. This can cause unpleasant situations, especially if the keys end up in the "wrong hands".

We can help you with this through our wide range of cylinder locks . You can rest assured that we can usually replace your locks in the Alkmaar region the same day.

It is of course also possible for you to pick up the cylinders at the store, or order them via the online store to install them yourself. Because we are able to make cylinders keyed alike, we can supply you with all conceivable sizes with the same key, which provides you with a lot of ease of use. If you order them before 3:00 PM, they will be shipped the same working day.

Extensive range of more than 15,000 items

Whether you are looking for locks, hardware, tools, hardware or electricity; Postma and Postma has it all. With more than 15,000 items, we almost always have what you are looking for.

Shop and showroom in the center of Alkmaar

Are you nearby? Then you are always welcome in our store and showroom in Alkmaar. There you can view our hinges and locks at your leisure - and we will be happy to advise you about the possibilities.

Lightning-fast key and lock service

Have you lost a key? Or is your lock broken? You can use our key and lock service during opening hours. We make your key while you shop - or replace your lock on location.

Would you like to talk to one of our specialists?

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