CNC Machining calculator
Ball Nose Scallop Height Calculator
Use this calculator to connect 3D surfacing step-over choices with expected cusp or scallop size. It helps CNC programmers and quality teams balance surface finish, polishing time, machining time, and tool diameter selection.
What this calculator does
- Estimate ball-nose scallop height from step-over, tool radius, and a finishing factor for surfacing operations.
- screening finish-machining step-over for molds, dies, contoured parts, and 3D surfacing work
- The result is an estimated scallop-height indicator for comparing finish strategies.
Formula used
- Ball Nose Scallop Height = step-over basis ÷ ball-nose tool radius basis × finishing factor
- Keep numerator and denominator on the same job, setup, tool, or production basis.
Inputs explained
- step-over basis: Use the measured numerator from the same job, batch, cutter, fixture, or machining scenario.
- ball-nose tool radius basis: Use the matching denominator from the same operation, lot size, tool life record, or setup plan.
- finishing factor: Use 1.0 when no conversion or adjustment is needed; otherwise use the documented shop factor.
How to use the result
- Use it when selecting step-over for contour milling, mold finishing, or post-machining polishing targets.
- Treat the result as a planning estimate until it is verified against the actual CNC program, machine limits, toolholder rigidity, coolant delivery, workholding, material condition, inspection data, and shop-floor trial results.
Common questions
- What is the ball nose scallop height calculator for? It calculates ball nose scallop height for a specific CNC setup or costing question.
- What information should I enter? Use step-over basis, ball-nose tool radius basis, and finishing factor from the same routing, quote, tool record, or production run.
- What does the result tell me? The result is an estimated scallop-height indicator for comparing finish strategies.
- When is the result only an estimate? Treat the result as a planning estimate until it is verified against the actual CNC program, machine limits, toolholder rigidity, coolant delivery, workholding, material condition, inspection data, and shop-floor trial results.
Last reviewed 2026-05-12.