1/4" 2-Flute Ballnose Spiral
The 3D bit. An up-cut spiral that ends in a 1/8” radius ball instead of a square corner, ground to Amana’s high-mirror finish. Everything with a curved surface — carvings, reliefs, rounded pockets — comes off this tool.
Specifications
| Property | Value |
|---|---|
| Cutting diameter | 0.250” |
| Ball radius | 0.125” |
| Shank diameter | 0.250” |
| Flutes | 2 |
| Cutting length | 0.875” |
| Overall length | 2.500” |
| Geometry | Up-cut spiral, ball end |
| Material | Solid carbide, high mirror finish |
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. Stepover is the 3D-finishing pitch between parallel passes.
| Material | RPM | Feed | Chipload | Plunge | Stepover |
|---|---|---|---|---|---|
| Hard maple / oak | 16,000 | 180 ipm | 0.0056” | 30 ipm | 0.025” |
| Soft maple / walnut / cherry | 16,000 | 200 ipm | 0.0063” | 30 ipm | 0.025” |
| Plywood | 16,000 | 220 ipm | 0.0069” | 35 ipm | 0.025” |
| MDF / laminate | 18,000 | 250 ipm | 0.0069” | 40 ipm | 0.030” |
| Softwood / pine | 18,000 | 250 ipm | 0.0069” | 40 ipm | 0.030” |
| Acrylic / HDPE | 14,000 | 150 ipm | 0.0054” | 25 ipm | 0.020” |
The chipload column is the full-slot number; in a finishing pass the ball is barely engaged and the real chip is far thinner, which is why these sit at higher RPM than U01 without rubbing. The tip itself has near-zero rim speed, same story as V01.
Notes
This is a finishing tool. For 2D slotting or profiling at full depth, U01 does it better — square corners, proper chipload at 14,000. The presets here assume Parallel or 3D Contour passes over a roughed shape.
Stepover sets the scallop. At 0.025” between passes a 1/4” ball leaves ridges about 0.0006” tall — sandpaper territory. Halving the stepover quarters the scallop and doubles the runtime; going coarser shows tool marks fast.
Rough first with U01, leaving 0.02–0.03” of stock. The ball then cuts a consistent thin skin everywhere instead of alternating between air and full slots.
The mirror-finish grind is aimed at plastics. Amana sells this line for acrylic and HDPE surface work; the acrylic preset is its home turf, not an afterthought.
Links
- Product page: Amana Tool 46379
- Machine: X-Carve Pro
- CAM library: Fusion hub library, Human Crafted