FYI: According to what my Friend told me,who owns a LQS here in our area, when you hear your blade/rotary cutter making the clicking noise, there is something wrong with your rotary cutter and not the blade... this was what her olfa rep told her...I am not sure but she also said it may be the mat as well..just sharing this so if you are still hearing the clicking and you put in a new blade, check to tool as well...