Contact failure of the contact occurs. When it is pressed with a holding type switch, it comes into contact, but when it is held, it breaks. It seems that it is in the contact when it is in the holding state. I tried to bend the movable terminal slightly downward, and it worked normally. Both of the two bought the same symptoms. Therefore, I purchased two for this time for the spare.
For the emergency stop pushbutton switch of the monotaro brand, there was only b contact, I was looking for the contact a place I found it so that I could use a part so I ordered it. Very easy to use. It will be helpful if you can arrange the models that you incorporated from the beginning. I like it because the hardness of the push spring is just right.