FREE TOOL
CNC Cutting Calculator
Speeds, feeds, MRR & machining time for milling, turning & drilling
Speeds, feeds, MRR & machining time for milling, turning & drilling
CNC cutting calculation determines the optimal spindle speed, feed rate, and cutting parameters for machining operations. Proper speeds and feeds ensure good surface finish, long tool life, and efficient material removal. The calculations are based on cutting speed (surface speed), tool diameter, number of flutes, and feed per tooth.
CNC programmers: calculate optimal cutting parameters. Machinists: verify and adjust speeds and feeds. Students: learn machining fundamentals. Shop owners: estimate machining time for quoting. Tooling engineers: optimize tool life and productivity.
Select your machining operation (milling, turning, drilling). Choose the workpiece material. Select the tool material (HSS, carbide, ceramic). Enter tool diameter and number of flutes. Set cutting depth and width. Enter feed per tooth. Enter cutting length for time estimation. Results update instantly.
Cutting speed (Vc) is the relative surface speed between the cutting tool and the workpiece, measured in meters per minute (m/min). It's determined by the workpiece material and tool material. Harder materials require lower cutting speeds. Carbide tools allow higher cutting speeds than HSS tools.
Feed per tooth (fz) is how much material each flute removes per revolution, measured in mm/tooth. Feed rate (Vf) is the total speed the tool moves through the material, measured in mm/min. Feed rate = RPM 脳 number of flutes 脳 feed per tooth. Feed per tooth is the fundamental parameter; feed rate is the machine setting.
MRR is the volume of material removed per unit time, measured in cm鲁/min. It's calculated as: MRR = depth 脳 width 脳 feed rate. Higher MRR means faster machining and higher productivity. However, higher MRR also increases tool wear and heat, so there's a balance between speed and tool life.
Feed per tooth depends on tool diameter, number of flutes, material, and operation. General guidelines: roughing = 0.1-0.2 mm/tooth, finishing = 0.05-0.1 mm/tooth. Smaller tools need lighter feeds. Harder materials need lighter feeds. Always start conservative and increase while monitoring tool wear and surface finish.
These calculations provide good starting points, but real-world conditions vary. Factors like machine rigidity, tool holder quality, coolant type, workpiece fixturing, and specific alloy composition all affect optimal parameters. Always verify with test cuts and adjust based on actual machining results.