There are several methods to make the strut-profile teethes, some can make the teethes well and some can not. Here let me give you some explanation. Teethes making as below is better, this can guarantee the teeth is more deep and teethes are located in the top of the metal and then the force of friction is better. 

And at the same time, this type teethes making can guarantee the teethes rollers longer lifetime. As we can see, there are roller spacers on the shaft, so after the teethes rollers is worn then we can change the teethes position to guarantee the teethed rollers can use many time. What our machine adopt is this method to make the teethes for the strut-profile. 

There are some other ways to make the teethes, but finally we find the result is not so good, here let me share some photos with you, so nowadays we already do not use this type method to make the teethes for the c strut-profile machines.