Most superficial wounds that do not bleed do not require tetanus, but when the wound is thin and deep, tetanus may be required.
No bleeding means that the wound is very superficial, not to a very deep location, tetanus bacillus needs to be in a suitable anaerobic environment to be able to reproduce, the wound is relatively shallow is an aerobic environment, in such an environment tetanus bacillus is difficult to survive, it is not easy to form an infection, and therefore do not need to take a tetanus shot.
When the wound is thin (e.g., stabbed with a needle) and the location of the wound is deep, even if there is no bleeding, the environment of the wound may be suitable for tetanus bacilli to multiply, so it is necessary to consider taking a tetanus shot.
You can also go to a regular hospital in time after the injury without bleeding, and the doctor will decide whether you need to get a tetanus shot.