The one-pin lock

Eurocylinders have a standard form factor, but they come in different sizes. In the middle is the cam and the screw to attach the cylinder to the door. Measuring the lengths from the center of the cam to both ends gives you the length, for instance, 30/30 is a popular size. This means both ends are 30mm or 3cm for a total length of 6cm.

Although sizes of 30mm and 35mm (or combinations with 10mm for half cylinders) are pretty normal, there’s quite a variation in lengths, especially if you go to Belgium for instance.

A 45/55 cylinder

Very long ones such as the 45/55 above, are quite rare. Ones shorter than 30 are also rare. I had come across a 25/25 once, but a while ago, my favourite locksmith from Oostende (Birger) gave me a 20/20 cylinder.

A 20/20 cylinder

It did not come with a key. The cylinder only has one pin! This means that any key that fits the keyway can be used to open it: just insert the slope of the key just far enough to push the pin to the shear line.

By not inserting the key fully, we can pick the one pin

The cylinder did not come with a key, so I used impressioning to make one.

The impressioned key

Photos CCBY4.0 Walter @ Toool Blackbag

One Response to “The one-pin lock”

  1. NKT says:

    That’s hilarious! A good beginner’s lock!

Leave a Reply