What tool is being used? spinning at what speed?
What CAM tool is being used?
Is it a slotting toolpath? Is adding geometry so as to cut as a pocket and leaving a roughing clearance and then taking a full-depth finishing pass an option? Where possible avoid slotting and add geometry and cut as a pocket (Making vacuum hose adapters and/or Adding geometry to cut as a pocket with a finishing pass ) and consider leaving a roughing clearance and taking a finishing pass.