The service life of contact shrapnel is generally relatively long, and the life of some contact shrapnel can reach 1 million times. Common failures of contact shrapnel are as follows: Over-travel: For example, when the shrapnel is pressed by hand, the travel is uncontrollable, which may cause over-travel and destroy the shrapnel. Overpressure: For example, when pressing the shrapnel by hand, the pressure is uncontrollable, and the load may exceed the normal preset pressure value of the shrapnel, which may cause overstroke and damage the shrapnel. Excessive crushing: Use sharp objects or nails to cause shrapnel scratches. The contact is too large: the contact design is unreasonable, causing the contact to not work well with the shrapnel, which affects the normal use of the shrapnel. Unbalanced shrapnel contact surface: the periphery of the shrapnel is unbalanced. Poor contact: install shrapnel reasonably and pay attention to reserve space for shrapnel. Resistance value: The resistance value of the shrapnel is relatively fixed, for example, stainless steel is less than 100 ohms, nickel plating is less than 1 ohm, and gold plating is less than 0.1 ohm. When using contact shrapnel, pay attention to the following methods: Contact shrapnel contact: The size must be used in conjunction with the shrapnel, or the size of the contact should be matched with the shrapnel to avoid excessive crushing by the shrapnel. Overpressure: All shrapnels have a preset positive pressure value. If the pressure is too high, the shrapnel will be damaged.