Iron palm can be a formidable technique to have in a fight.  A well-placed strike can disable an attacker immediately.  However, it can also be a danger to the practitioner if it is practiced incorrectly.

A common mistake made by beginners to iron palm training is to use too much force to hit the bag.  The hand should be “dropped” onto the bag, not slammed down with force.  Using too much force can cause damage to the hand, especially if the practitioner is a beginner and hasn’t built up a general level of conditioning yet.  An injury such as this can cause the student to have to sit out from training for days or weeks as it heals, which can delay the development of his technique.

Another reason some kung fu schools teach against hitting the bag too hard is because it can send shockwaves back up the arm and into the body of the student, which can be surprising and throw off the student’s concentration, as well as possibly causing damage to the body over time.

It is important to use dit da jow when doing any contact training.  Dit da jow promotes healing which takes place between training sessions.  If the hands are not fully healed by the time for the next training session, the student risks damaging his hands.  This is especially true if delicate areas such as the fingertips are being trained.

Another mistake is to try to progress too quickly.  Palm training takes months and years, not days or weeks.  Traditionally, over time a student will progress to training on bags filled with harder materials, such as beginning with a bag filled with mung beans or rice, and then eventually progressing to a bag filled with pebbles, and then maybe a bag filled with steel shot.  If a student progresses to the next bag before he is ready, he can damage his hands by striking material that is too hard for him at that point in time.

It has been said that people who practice this technique have sometimes caused damage to things on accident as a result of their training.  An advanced student who is not mindful of the amount of power in his hands may accidentally damage objects if he is too rough and careless with them, or may even harm people as well, for example a “playful” slap may end up doing more damage than intended.