I found this gif, and I was wondering how much force is applied on the pin due to the spring from the top? Also, is there an industry standard for the amount of force exerted?

lock tumbler animation

  • $\begingroup$ You know the more the pin deflects the higher the spring force. So there isn't a constant value, but there is a max value depending on the width of the key. $\endgroup$ Apr 7 '15 at 21:02

Hooke's Law

The force of applied by the spring to the pin, will depend on how much the spring is compressed. This can be calculated by using Hooke's Law:

enter image description here

Finding k (Using assumptions)

In order to find find k, for demonstration we will just assume a few properties of the spring based on what we can see in the gif.

Spring Constant Calculator

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k = 0.136 N/mm

Finding X maximum

For demonstration we will use 3 mm for the maximum compression of the spring.

Calculating Maximum Force From Spring

Using the assumed properties and plugging them into Hooke's Law.

F = k X

F = (0.136)*(3)

F = 0.408 N

Industry Standards

This type of lock is a Tumbler Lock and the spring force is most likely not regulated or standardized in industry, but other contributors may have more information.


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