Can I put my bank card and ID card together? Why?

You can put them together. ID cards and bank cards are not strong magnetic fields, and mobile phones are not strong magnetic fields, so don't worry.

Magnetic stripe cards are mainly divided into two categories, one is weakly diamagnetic and the other is strongly diamagnetic.

Weak diamagnetism is generally used for disposable cards such as park tickets, while strong diamagnetism is often used for items such as bank cards.

For the weak diamagnetic magnetic card, the magnetic field generated by the current of about 10 A can demagnetize it; For magnetic cards with strong diamagnetism, the magnetic field generated by the current of about 100 A can demagnetize them.

The current of a mobile phone is generally 700 mA to 1000 mA, and 1000 mA is 1 amp, so the magnetic field generated by the mobile phone is not enough to degauss the magnetic stripe bank card.

For IC bank cards (chip cards) inlaid with yellow metal sheets, there is no need to worry about degaussing.

Extended data:

Matters needing attention in using magnetic stripe card

1. The locks of some backpacks and wallets are "hidden buttons" made of magnets, so the cards should be kept away from such magnets.

2. Don't let the card near the high temperature environment or humid environment. Generally, the material of magnetic stripe card is PVC, which will be deformed or even burned at high temperature, which will directly lead to the damage of magnetic stripe. If the magnetic stripe card is placed in a humid environment or soaked in water for a long time, it will also lead to card opening and damage, and eventually it cannot be used.

3. Do not bend the card, and prevent sharp objects from wearing, scratching or twisting the magnetic stripe. Several cards were put together and rubbed against each other. Although the card cannot be degaussed, the magnetic stripe area will be damaged. So it's best to put the card in a special card bag or in a protective case.

References:

People's Network-Why do bank cards degauss? The mobile phone means "this pot doesn't carry back"