1/4" 2-Flute Upcut Spiral
The one unlabelled bit in the drawer. No vendor markings beyond 1/4 81618 engraved on the shank, and that number doesn’t match any catalogue I can find — most likely a reseller SKU or a batch code. Every figure below was measured rather than looked up.
Specifications
| Property | Value |
|---|---|
| Cutting diameter | 0.250” |
| Shank diameter | 0.2475” (nominal 1/4”) |
| Flutes | 2 |
| Cutting length | 1.240” |
| Overall length | 3.015” |
| Geometry | Upcut spiral |
| Corner radius | None — square end |
| Material | Solid carbide |
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, so picking the tool in CAM loads them automatically.
| Material | RPM | Feed | Chipload | Plunge | Stepdown |
|---|---|---|---|---|---|
| Hard maple / oak | 14,000 | 220 ipm | 0.0079” | 60 ipm | 0.250” |
| Soft maple / walnut / cherry | 14,000 | 240 ipm | 0.0086” | 60 ipm | 0.250” |
| Plywood | 16,000 | 280 ipm | 0.0088” | 70 ipm | 0.250” |
| MDF / laminate | 16,000 | 300 ipm | 0.0094” | 70 ipm | 0.375” |
| Softwood / pine | 16,000 | 300 ipm | 0.0094” | 70 ipm | 0.375” |
| Acrylic / HDPE | 12,000 | 200 ipm | 0.0083” | 40 ipm | 0.125” |
The X-Carve Pro caps feed at 300 ipm in firmware, so the MDF and softwood rows sit at the machine limit rather than at an ideal chipload. Everything else is set by dropping spindle speed rather than pushing feed — the 8,000 rpm floor on this spindle is what makes a proper chipload reachable at all.
Notes
Upcut geometry pulls chips up and out of the cut. That keeps deep slots clear and is the right choice for through-cuts in solid stock, but it lifts fibres at the top surface — so expect tearout on veneered sheet goods and figured hardwood unless a finishing pass cleans the edge up afterwards.
Cutting edge had dark deposits when catalogued, consistent with having been run at too low a chipload. Cleaned before measuring.
Links
- Machine: X-Carve Pro
- CAM library: Fusion hub library, Human Crafted