Cleveland
Cleveland C30839 5-Flute Cobalt Roughing End Mill
Five-flute cobalt roughing end mill for heavy material removal in milling operations
- TypeMilling
- 5-flute cobalt design removes material faster
- 8% cobalt alloy resists wear in tough steels
- 3 in length of cut reaches deep cavities
- 1 in shank fits standard Weldon holders
- Uncooked surface suits dry or flood coolant
Cleveland C30839 Roughing End Mill
The Cleveland C30839 is a 5-flute cobalt roughing end mill built for heavy material removal in milling operations. Its 8% cobalt construction provides the hardness and heat resistance needed for demanding metalworking tasks. This tool suits machinists and shops running aggressive roughing passes on ferrous alloys. It is not for finish profiling or non-metallic materials where a finer geometry is required.
Upgrade From Standard HSS Roughers
This end mill replaces general-purpose high-speed steel roughers when tool life and wear resistance become limiting factors. The cobalt substrate allows higher cutting speeds and feeds in tough steels and stainless alloys. The jump is worth it when frequent tool changes slow cycle times or when work hardening dulls standard cutters too quickly. It does not replace carbide roughers where maximum rigidity and speed are the priority.
Weldon Flat Shank Installation
The 1-inch shank with a Weldon flat locks securely into standard milling chucks and end mill holders using a set screw. Installation is straightforward on any machine equipped for 1-inch tooling. The non-coolant-through design means external flood coolant must reach the cutting zone effectively. Chip evacuation can become difficult in deep slots or pockets without adequate coolant pressure and chip clearance space.
Highlights
- 5-flute cobalt design removes material faster
- 8% cobalt alloy resists wear in tough steels
- 3 in length of cut reaches deep cavities
- 1 in shank fits standard Weldon holders
- Uncooked surface suits dry or flood coolant
Specifications
| Brand | CLEVELAND |
|---|---|
| Type | Milling |
Questions about this item
What shank diameter does the C30839 end mill need for a Weldon flat holder?
The tool has a 1 in shank with a Weldon flat, so it fits a standard 1 in Weldon holder.
How do I install the C30839 in a Weldon holder without it slipping?
Align the flat with the set screw, push the shank fully home, then tighten the screw firmly on the flat — not on the round body.
When should I replace the C30839 roughing end mill?
Replace it when the cobalt flutes show heavy edge wear, chipping, or when surface finish and chip load degrade noticeably.
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