📓 INTERACTIVE CALCULATOR

Deep Hole Tool Life Estimator

Enter your current cutting speed, feed and tool life, then a proposed new speed and feed — the calculator predicts the new tool life using the extended Taylor equation, with exponents matched to your tool material.

Speed & Feed Change → Tool Life

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holes
Predicted tool life
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metres drilled
Equivalent drilled length
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%
Tool life change
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m/min
Speed change

Based on the extended Taylor tool life model (V · Tn · fy = C) — cutting speed is the dominant lever, feed second. Predictions are planning estimates: real life varies with workpiece hardness, runout, coolant condition and regrind quality.

Typical Deep Hole Tool Life (published)

Tool & applicationReported lifeSource
Carbide gundrill, Ø10.5 mm, transmission shafts~200–340 holes per toolCarbide gun drill study (K40UF)
Indexable carbide drill, 4340 steel, 0.937 in320 holes per insertAllied Machine 4TEX case study
Coated carbide drills (wear test)500 (uncoated) / 3,400 (TiAlN) / 4,000 (AlCrN) holesReground-carbide comparison study
Gundrill regrind interval~50–200 m drilled length per regrind (by material)Deep Hole Drilling Guide — Tool Regrinding
⚠️ The 0.4 mm rule: the standard tool life criterion for drilling is average flank wear of 0.4 mm — beyond that, re-set or regrind. Watch the trend, not the alarm: a gundrill’s coolant-pressure and spindle-load trend rises as the edge dulls, well before the finish degrades.

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