You will see chatter in various frequencies, as it were. A squealing sound will indicate a high frequency chatter with the result being, lots of flutes but fairly shallow. The lowest frequency will produce six, very significant, flutes. You should feel this one. By the way, the flutes result from chatter will always appear in multiples of six. If the flutes are the result of reamer deflection in a five groove barrel, there should be five of them but sometimes, the deflection will set up the chatter which will result in the multiple of six. Sometimes, if the reamer starts to squeal, you can beat it by just increasing the feed rate but, if it doesn't quit right away, you had better stop and wrap or pack the reamer to settle it down. WH