So I have this 125khz RFID card and I would like to punch a hole in it so I can have a thin string go through it, making my card to be able to hang from my neck.

Though I have no experience in punching hole to any sort of card, not mentioning an RFID one.

  1. Is it possible to punch a hole through the RFID card and still have it work properly?

  2. How should I punch a hole through the RFID card safely, easily and using some cheap accessible tools (list of alternative ways to punch a hole into RFID card is welcomed)

  3. In the picture below, you can see my RFID card in front of a light source, showing the antenna. On the picture, I put a green circle to the place where I need the hole to be (though I can make the hole a little bit smaller as long as a double-string can pass through). Is that a safe distance? Is the whole too big? Is there a chance that it will break the card?


my RFID card

Note: please make your answers to be understandable for an average person like me (who is not deep into this field yet)


Thanks to @Passerby for the answer. I suggest using the heated needle method if you have a needle lying around somewhere and don't have any special tools. I can confirm that it works perfectly (see image below)

the result

Also special thanks to @DarkCygnus for his help in finding this StackExchange.

  • \$\begingroup\$ Why does it have to be on that green circle? \$\endgroup\$
    – longneck
    Sep 25 '18 at 17:48
  • 1
    \$\begingroup\$ @longneck because I have a card template which I plan to stick on the card and the card template already has a hole punched. \$\endgroup\$ Sep 25 '18 at 17:54
  • 2
    \$\begingroup\$ I would put the hole on the short side, it can be further in and that refuces the change the string will pull through... \$\endgroup\$
    – Solar Mike
    Sep 25 '18 at 18:00
  • \$\begingroup\$ No conductors can be facing the circle near the hole so plastic or nylon strands are OK. Punches which slide over the edge on both sides exist must have sharp square edges and a slope or cutting angle for easy cutting, much stronger than a paper punch. Otherwise small diameter punch and slot tools must be aligned by tooling design. IF mass produced, then a board shop can do this. \$\endgroup\$ Sep 25 '18 at 18:01

They punch holes in RFID cards all the time. Using a hand or desk hole punch. The smarter companies order them with the holes pre punched. A hand hole punch is fine if you are no where near the coil or IC, otherwise you risk breaking the coil. You may also risk opening the inner layers of the rfid card to the elements if you open it in the wrong place.

The spot you illustrate with green, is just asking for trouble. A millimeter in and you just cut the coil.

Alternative, glue something to the back that would let you attach a rope, like a small piece of fabric or plastic. Or use/make an pouch or card holder.

  • \$\begingroup\$ I see. Is there a way to create like really small holes (like half the size of the typical hole of a hole puncher)? \$\endgroup\$ Sep 25 '18 at 18:28
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    \$\begingroup\$ A hardware punch and hammer. A drill. A needle and lighter to melt a hole. A nail and hammer. A nail and a lighter. The problem is simply you need to be sure your not cutting the coil. If you can easily replace the rfid card, then messing up isn't an issue, but if you can't... \$\endgroup\$
    – Passerby
    Sep 25 '18 at 18:34
  • \$\begingroup\$ using a needle sounds the safest (and the most accessable). Do I like heat the area with the lighter and then hammer a needle through the card? Will the card crack? will the card stop working if I heat it using a lighter? \$\endgroup\$ Sep 25 '18 at 18:36
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    \$\begingroup\$ Heat the needle, In pliers. Push the hot needle through the plastic. Don't breathe in the fumes. \$\endgroup\$
    – Passerby
    Sep 25 '18 at 19:08
  • 3
    \$\begingroup\$ I can confirm that pushing a hot needle through the plastic works like a charm! Thanks. Also really appreciate the warning about the toxic fumes from the plastic. \$\endgroup\$ Sep 25 '18 at 22:15

Use a "slot hole punch" like this


to keep away from the antenna element. Also check the card for some dots or other marking to help with identifying where to make the slot.

  • 5
    \$\begingroup\$ The 3x15mm hole from that would be less risky than the 9/16" (~7mm) hole from a standard round hole punch in the US, but is still close enough to make me nervous. Like @SolarMike suggested in a comment I'd recommend either punching the short side away from the chip, or if the card needs to be horizontal to punch 2 holes in opposite corners and run a string/lanyard from one to the other. \$\endgroup\$ Sep 25 '18 at 19:42

The best way is to put your RFID card in a card holder, then attach the cardholder to your lanyard. Your employer should provide one, otherwise the card will get lost.

  • \$\begingroup\$ While this doesn’t specifically answer the question, it’s probably the best solution. \$\endgroup\$ Oct 3 '18 at 1:24

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