Oversize Holes
Misalignment, Vibration, Chatter
Runout of reamer chamfer
Poor hole preparation
Excessive stock removal
Reamer hitting bottom in blind hole
Dull reamer
Incorrect or damaged reamer

Undersize Holes
Excessive wear
Improper reamer size
Improperly sharpened reamer

Bellmouth Holes
Misalignment, Vibration, Chatter
Bent reamer shank
Excessive tool overhang

Poor Finish In Holes
Dull or damaged reamer
Incorrect reamer
Misalignment, Vibration, Chatter
Excessive stock removal
Poor machinability on material being removed
Tool marks

Oversize Holes-Solution
Decrease cutting speed
Resharpen reamer
Check drill size
Realign work-piece and holder
Remove less material
Check reamer size

Undersize Holes-Solution
Replace reamer
Resharpen reamer
Check reamer size

Bellmouth Holes-Solution
Decrease reamer overhang
Resharpen reamer

Poor Finish In Holes-Solution
Remove less material
Resharpen reamer
Replace reamer
Adjust speeds
Use different type of reamer
Check material