1/4" 2-Flute TiCN End Mill (metal)
The longer, two-fluted sibling of U02 — same Kyocera line, same TiCN coating, same 30° helix, but two flutes instead of three and 1-1/8” of cut instead of 3/4”. Those two changes matter more than they sound: two flutes means real chip gullets, and 1.125” means it can actually cut through 3/4” stock.
Specifications
| Property | Value |
|---|---|
| Cutting diameter | 0.250” (tolerance −0.0020” / +0.0000”) |
| Shank diameter | 0.250” |
| Flutes | 2, equal spacing |
| Cutting length | 1.125” |
| Overall length | 3.000” |
| Helix angle | 30° |
| End type | Square, centre cutting |
| Material | Solid carbide |
| Coating | TiCN (titanium carbon nitride) |
| Manufacturer | Kyocera |
Feeds & Speeds
For the X-Carve Pro and its 1.5 kW spindle. These match the presets stored on this tool in the Fusion hub library.
| Material | RPM | Feed | Chipload | Plunge | Depth of cut |
|---|---|---|---|---|---|
| Aluminium — adaptive | 12,000 | 90 ipm | 0.0038” | 15 ipm | to 0.375” at ~10% radial |
| Aluminium — slotting | 10,000 | 50 ipm | 0.0025” | 12 ipm | 0.030” |
| Brass / bronze | 12,000 | 90 ipm | 0.0038” | 15 ipm | 0.060” |
| Fibreglass / G10 | 12,000 | 70 ipm | 0.0029” | 15 ipm | 0.060” |
| Plastic | 10,000 | 110 ipm | 0.0055” | 20 ipm | 0.060” |
| Hardwood — backup only | 14,000 | 200 ipm | 0.0071” | 40 ipm | 0.125” |
Aluminium chiploads run higher than on U02 despite similar feeds, because two flutes divide the feed two ways instead of three. Two flutes is also the better aluminium geometry — more room per chip, and aluminium makes long stringy ones.
Notes
This one tolerates wood, unlike U02. Two flutes is the correct count for timber, and there is enough cutting length to go through 3/4” stock. But it is still a metal-cutting end mill: the gullets are tighter than a router spiral’s and the rake is less aggressive, so it packs sooner and burns more readily. Reach for U01 first and treat this as the spare when U01 is dull or already in the collet for something else. There is a hardwood preset for exactly that situation, marked backup only.
Lubricate in aluminium. Aluminium has an affinity for titanium-based coatings and will gall onto TiCN. WD-40 or denatured alcohol, misted. ZrN, DLC, or polished uncoated carbide would be the right coating for aluminium — this works in spite of its coating, not because of it.
Steel is out of reach, same as U02. A 1/4” carbide end mill in mild steel wants 4,000–5,300 rpm; the X-Carve Pro floors at 8,000. No coolant, no rigidity, no ferrous work.
Diameter runs undersize by design — up to 0.002” small. Noise in wood, but on a precision aluminium fit it leaves outside profiles up to 0.002” oversize. Measure a test cut and set a wear offset when the fit matters.
Fibreglass and G10 are where the TiCN genuinely earns its place — abrasive enough to strip uncoated carbide. Extraction and a respirator; the dust is a lung hazard.
Links
- Product page: McMaster-Carr 8515A31
- Machine: X-Carve Pro
- CAM library: Fusion hub library, Human Crafted