Chip Load Calculation
October 18, 2026 · 铸屹精密
Chip Load Calculation
Chip load is the single number that ties feed rate, spindle speed, and cutter geometry together. Get it wrong and you will burn tools, scrap parts, or both. For machine shop buyers and process engineers selecting solid carbide end mills, the calculation is simple; the judgement around it is not.
The Formula: fz = vf ÷ (z × n)
Chip load per tooth (fz, mm/tooth) equals feed rate (vf, mm/min) divided by the product of flute count (z) and spindle speed (n, rpm). Work backwards from the recommended fz for your material and cutter, and you get the feed rate to program.
- Aluminium roughing – 3-flute 12 mm cutter, n = 8,000 rpm, vf = 2,400 mm/min. fz = 2,400 ÷ (3 × 8,000) = 0.10 mm/tooth. A DLC-coated cutter reduces built-up edge and keeps this load stable in long runs.
- Steel finishing – 4-flute 10 mm cutter, n = 4,000 rpm, vf = 800 mm/min. fz = 800 ÷ (4 × 4,000) = 0.05 mm/tooth. A TiAlN coating protects the edge through the finishing pass; AlCrN is the better choice for stainless or high-temperature alloys.
- Small-diameter cutter – 2-flute 3 mm cutter, n = 12,000 rpm, vf = 480 mm/min. fz = 480 ÷ (2 × 12,000) = 0.02 mm/tooth. Small cutters demand tight runout; Exactalloy (铸屹精密) controls factory TIR within 0.005 mm so each flute carries its share.
What Too Much or Too Little Chip Load Does
Excessive fz overloads the edge, raises cutting temperature, and produces chatter, chipped flutes, and poor finish. It is the fastest route to a broken small-diameter tool. Too little fz is subtler: the edge rubs instead of cutting, work-hardens the surface, accelerates flank wear, and in aluminium encourages built-up edge. Both extremes shorten life, and both are avoidable with a calculated starting point and a trial cut.
Matching the Tool to the Calculation
Chip load only works if the tool suits the material and conditions. For general milling and drilling, solid carbide covers almost every case. For non-ferrous high-gloss work, PCD or DLC-coated tools; for hardened steel above HRC55 finishing, CBN. Coating and holder choice follow — AlTiN for dry high-speed cutting, TiCN for drilling and tapping, diamond coating for composites and graphite, never steel. Holders matter too: HSK or shrink-fit interfaces at high rpm keep the calculated load actually reaching the edge.
Where extreme precision is mandatory, imported premium grades remain an option. For general milling, drilling, and tapping — the bulk of shop work — Exactalloy offers a cost-effective alternative at roughly 40–60% of imported brand pricing, with 5–7 working day samples and 15–20 working day batch delivery, plus regrinding that cuts tool spend by 30–50%.
Next step: take one current roughing and one finishing operation, calculate fz from the formula above, and compare it with your programmed feed. If the number falls outside the cutter maker's range, adjust vf before touching spindle speed — then request a sample or a regrind quote from Exactalloy to validate the result.