Drill RPM Calculator
Calculate drill spindle RPM from cutting diameter and a user-sourced surface speed, with optional feed per revolution.
Open toolProfessional tool collection
Machining calculators
Feeds, speeds, tool geometry and production-planning calculations.
Separate geometry from recommendations: these tools solve transparent relationships using the cutting inputs you provide, without an embedded material or tooling database.
5 published toolsLatest technical review 2026-08-22
Workflow collection
feeds speeds
Choose the narrowest tool that matches the measurement or decision in front of you. Each page states its own source, model and exclusions.
Machining Time Calculator
Estimate cutting-feed time and a transparent cycle total from manual path, feed, rapid and fixed-time inputs.
Open toolRadial Chip-Thinning Calculator
Calculate programmed chip load and feed for light radial engagement within a documented 90-degree peripheral end-mill model.
Open toolSurface Speed Calculator
Solve surface speed, spindle RPM or effective diameter with exact π in metric or inch units.
Open toolWorkflow collection
toolpath geometry
Choose the narrowest tool that matches the measurement or decision in front of you. Each page states its own source, model and exclusions.
Cusp Height & Stepover Calculator
Calculate theoretical cusp height or stepover for adjacent planar passes of a spherical ball-nose profile.
Open toolMeasure and verify
Practical guides
Building an auditable machining-time estimate
Separate cutting-feed time, rapid motion, tool changes and fixed delays for a transparent estimate.
Read guideHow to Collect Chip Load, Feed, RPM, and Tool Inputs
Record effective teeth, cutter diameter, operation, engagement, source ranges, and machine limits before calculating CNC feed relationships.
Read guideHow to source cutting speed, chip load and feed values
A traceable method for collecting manufacturer inputs without turning a formula calculator into a recommendation table.
Read guideWhat theoretical cusp height does—and does not—predict
Apply the planar spherical-profile equation correctly and avoid confusing geometric cusp with measured surface finish.
Read guideWhen the Radial Chip-Thinning Formula Applies
Understand the 90-degree peripheral end-mill geometry, engagement boundary, target chip thickness, and limitations of radial chip-thinning correction.
Read guideScope and review
Every published engine uses explicit units, retains full internal precision, and shows assumptions with the result. Check the page references and review date before purchasing material or using an estimate in professional work.
See the source and update policy or search every published tool.