Piercing tool

A piercing tool, comprising:

• a distal end portion, which has a cylindrical shape, and is to be first brought into abutment against an object;
• and
• a main body portion, which has a cylindrical shape at at least a part of the main body portion, and has one end portion to which the distal end portion is mounted,
• wherein the distal end portion is removably mounted to the one end portion of the main body portion, and has an inner peripheral surface having a female thread formed at an end portion of the distal end portion on a side to be mounted to the main body portion,
• wherein the main body portion has an outer peripheral surface having a male thread formed so as to be engaged with the female thread at the end portion of the main body portion on a side to which the distal end portion is mounted,
• wherein the distal end portion has a Rockwell hardness higher than a Rockwell hardness of the main body portion,
• wherein the male thread includes an incomplete thread portion formed in an inner end portion area away from the one end portion of the main body portion, and
• wherein the incomplete thread portion is a portion that engages with a part of the female thread of the distal end portion in a non-normal state, and is formed in a shape in which valleys of the male thread become shallower as being away from the one end portion of the main body portion.