Tools keep breaking? Here's how to stop it.
A broken tool isn't bad luck — it's almost always the grade, the edge prep, the grip, or the speeds and feeds telling you something. Fix the cause and breakage stops.
Why it happens — and the fix
1Wrong grade or coating for the material
Match the substrate and coating to the heat and abrasion of the cut — AlTiN (Scorpion Stinger) forms a heat shield for hardened steel, titanium, and Inconel; DLC (Black Mamba) keeps aluminum from welding to the edge. The right coating moves heat into the chip instead of the carbide.
2Edge is too sharp for the material (chipping)
A razor edge chips in steel and super alloys. RobbJack's T-Process hones and strengthens the edge to eliminate chipping while keeping it smooth — just don't use it in aluminum or plastics, which want a sharp edge.
3The tool is pulling out of the holder
RobbJack's anti-pull-out shank (an h4 tolerance, the tightest in the industry) adds up to 150% more gripping force — enough to hold full slots in aluminum at over 200 HP. Don't grind your own Weldon flats; the flat width is held under .001" to lock against the set screw, and RobbJack grinds flats (-FL) for free.
4Too much stickout and deflection
Use the shortest tool that reaches the cut, and for deep pockets use a necked tool — a neck is far more rigid than a long flute length, so it deflects and breaks less. RobbJack adds necks and reach to standard tools in 1–2 days.
5Wrong speeds and feeds — rubbing or overloading the edge
Too light and the tool rubs and work-hardens the cut; too heavy and it overloads. Start from RobbJack's tested data instead of guessing — the calculator gives roughing and finishing numbers for your exact tool and material.
6Chatter cracking the edge
Vibration fatigues carbide. A variable-helix tool damps the harmonic, and Mirror Edge geometry is built to eliminate chatter on thin walls and deep pockets — both protect the edge.
The proof
- 150%
- more shank grip — anti-pull-out h4 shank
- 200+ HP
- full-slot aluminum cuts without pull-out
- Free
- factory-ground Weldon flats (-FL)
Dig deeper
Not sure where to start?
Send us your toughest part. Our application engineers will recommend the tool and the numbers.