Cutting modes calculator online

Cutting speed (V_c) is the linear speed at which the tool's cutting edge moves relative to the workpiece surface. It is measured in m/min (meters per minute).

Cutting speed is the primary parameter, selected from tool manufacturers' catalogs depending on:

• ISO material group (P — steel, M — stainless steel, K — cast iron, N — non-ferrous metals, etc.);
• material hardness (HB or HRC);
• the tool material itself (carbide, high-speed steel HSS, ceramic) and its coating (TiAlN, AlTiN, etc.).

From the recommended cutting speed, spindle speed (n, rpm) is calculated as:

Where:

• D — effective tool (cutter) diameter or machining diameter (for turning), mm;
• π — mathematical constant (≈ 3.14159).

⚠️ Consequences of mistakes: If the cutting speed is too low, the tool works inefficiently, which can cause built-up edge. If it is too high, the temperature in the cutting zone rises critically, leading to rapid plastic deformation or micro-chipping of the carbide insert.

Feed defines how far the tool moves per unit of time or per revolution.

Feed per tooth (f_z, mm/tooth): The chip thickness removed by one cutter tooth per pass. It is the basic milling parameter that ensures the teeth actually cut the metal instead of rubbing against it.

Feed per revolution (f, mm/rev): Used directly in turning and drilling. In milling it equals:

Where z is the number of cutting edges (teeth) on the cutter.

Table feed (F or V_f, mm/min): The feed rate that we program directly in G-code (address F). It is calculated for both milling and turning:

For a complete analysis of cutting modes, besides speed and feed you must account for the geometric parameters of the metal layer being removed:

Axial depth of cut (a_p, mm): The depth to which the tool plunges into the material along its axis in one pass.

Radial width of cut / stepover (a_e, mm): The milling width, or the offset step (stepover) between adjacent passes.

When radial engagement decreases (a_e < 0.5 × D), chip thinning occurs. In this case the actual chip thickness becomes smaller than the programmed feed per tooth f_z. To compensate for this effect and protect the tool from rubbing and work hardening, the table feed must be increased proportionally.

Machine–fixture–tool–workpiece (MFTW) rigidity: Machine condition, fixture rigidity (vise, chuck), tool stick-out and part geometry directly affect vibration. With low rigidity, the calculated modes should be reduced (a_p or f_z).

Coolant: Using cutting fluid or compressed air is critical for evacuating chips from the cutting zone. Re-cutting chips (especially in deep pockets or slots) is the main cause of sudden end mill breakage.