To connect two plastic pipes 3 together, an induction connection sleeve 1 is used, which is provided with annular recesses 5 into which the pipes 3 with the ends 3A are pushed. Subsequently, induction heating elements 9 present in the induction connecting sleeve are heated with induction hand pliers 21 and the induction connecting sleeve is pressed against the end 3A of one of the tubes 3. The induction connection sleeve fuses to the tube. Because the induction hand pliers 21 are provided with ribs 27, grooves 19 are pressed into the pipe wall 3B in order to check whether sufficient heating and pressing has taken place over the entire circumference to obtain a gastight connection.