Troubleshooting
Poor Tool Life: Why Your End Mill Wears Out Too Fast
Burning through end mills? Most premature wear comes from too much surface speed, too little chip, or not enough coolant. Here's how to diagnose and fix it.
Carbide should give you predictable, repeatable tool life — when it doesn't, the cause is usually heat or rubbing, not bad carbide. Too much spindle speed cooks the edge; too little chip load makes the flutes rub instead of cut and work-harden the material; too little coolant lets heat build where it does the most damage. Walk the causes below before you blame the tool.
Poor tool life — causes & fixes
The rubbing trap
Counterintuitively, running too slow on feed is one of the fastest ways to kill a tool. When the chip load per tooth drops below what the edge needs to bite, the flute rubs and burnishes instead of shearing — generating heat, work-hardening the surface ahead of the cut, and abrading the edge. The fix is to feed faster, not slower: get a real chip forming and the heat leaves with it.
Match the grade and coating to the job
When speeds, feeds, and coolant are right and life is still short, the substrate may be wrong for the material. RobbJack stocks multiple carbide grades and matches a coating — AlTiN for heat, DLC for non-ferrous, T-Process edge prep for ferrous toughness — to the application. The XG and SPS Super Python series are built specifically to hold an edge in the alloys that eat general-purpose tools.
Start from tested numbers
Guessing at speeds and feeds is how good tools die young. RobbJack's Speeds & Feeds calculator returns roughing and finishing numbers from 67 years of tested data for your exact tool and material — a reliable starting point you then tune to chip color and sound.
Pull RPM down, push feed up to a real chip, get coolant into the cut, and match the grade to the material — most 'bad carbide' is really bad parameters.
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