Not only does it depend on the depth of the cut by the steel, but the factors that determine the need for a tetanus vaccine include the cleanliness of the wound and the type of wound. Tetanus is triggered by the growth of spores of the tetanus bacteria in an anaerobic environment. Therefore, regardless of depth, tetanus vaccinations need to be considered for wounds caused by objects that may be contaminated with the tetanus bacillus. Overall, regardless of the depth of the scratch, if the wound is caused by an object that may be contaminated with tetanus bacilli, such as a steel bar scratch, it should be assessed by a healthcare professional to determine whether tetanus vaccination is required. The need for treatment of a wound is not determined by the depth of the wound alone; specific assessment and treatment should be carried out by medical staff. In any case, if there is any doubt, the help of a medical professional should be sought immediately. In real life, it is important to avoid injuries as much as possible, especially from sharp objects such as nails and needles. In the unlikely event of an injury, you should seek prompt medical attention.