Throughout his appearance in the One Piece series, the Monkey D Garp figure has displayed some of his strongest punching abilities. Monkey D Garp is known as one of the strongest Marines and one of the strongest characters in the One Piece story. Of course, this is quite extraordinary considering that Garp is different from other characters.
For example, if Gol D Roger or Shanks use their strength, which is then channeled into the sword so they can survive and fight, then Garp is different. He only trusts his own hands to flow the power of Haki. This combination causes Garp to have a deadly attack even though he only uses his bare hands. Here is the strongest hit owned by Monkey D Garp.
5galaxy impact

Galaxy Impact is the strongest punch Garp just displayed in One Piece history. This punch is arguably Garp’s strongest punch to ever appear in One Piece. Galaxy Impact Garp’s punch first appeared in chapter 1080 yesterday when SWORD and Garp tried to save Koby on Beehive Island.
This Galaxy Impact attack is, in fact, layered with Haki. This was shown where when the attack was carried out a black flash appeared around him. Besides being layered with Haki, one thing that stands out from the devastating power of Galaxy Impact’s attacks is the devastating power. It can be seen from the various buildings around his attack that were destroyed by this attack.