What is a good "standard" force for a momentary push-button?

:Title says it all. I'm trying to find information about what is a :good range for the force needed to activate a momentary push-button :switch. My application is to build a custom "d-pad" style array like :you might find on a video game controller or personal electronics. :But I'd also appreciate any links to empirical studies or published :papers on the subject. I'm having trouble getting Google to even come :close to the topic... :T :Thanks, :-Will

It is not possible to determine a "standard" force for push-buttons. It all depends on the purpose, environment and user mentality. In the latter case you have to take into account the idiot who will try to thump sh.t out of a push-button.

Designers of public use machines such as ticket issuing machines etc always find the selection of a suitable push-button is a major headache. To go for idiot proof design costs money and if you don't provide adequate mechanical strength you run the risk of having to constantly replace faulty units. One of the best foolproof push-buttons I saw was designed using no return spring or mechanical contacts. It used counter-posed supermagnets for the spring and hall effect switches for the outputs.

I have a great little silicone rubber keypad from an Asian maker that has a whole bunch of different actuation force sample buttons, as well as different contact types and so on. Very useful when you're designing a product that needs a keypad.

Best regards, Spehro Pefhany