Drilling · reaming · countersinking
Holemaking Calculators
Complete drilling math: spindle speed, penetration rate, metal removal rate, drill point depth compensation for through-holes, per-hole cycle time and tap drill selection.
Cutting speed → RPMFeed rate (penetration)Metal removal rateDrill point depthCycle time per hole / batch
Cutting speed → RPM
n = Vc·1000 / (π·D)Feed rate (penetration)
vf = fn · nMetal removal rate
Q = (π/4)·D²·vfDrill point depth
depth = (D/2) / tan(angle/2)Cycle time per hole / batch
t = depth / (fn·n)Formulas used
Drill point depth: (D/2) ÷ tan(point angle ÷ 2). A 118° point on a 10 mm drill adds ≈ 3.0 mm; a 135° point ≈ 2.07 mm.
Drilling MRR: Q = hole area × penetration rate = (π/4) × D² × vf.
Frequently asked questions
How deep is the point of a 118° drill?
Point depth = (diameter/2) / tan(59°) ≈ 0.3 × diameter. For a 10 mm drill that is about 3.0 mm — program Z to the full-diameter depth plus point depth plus clearance for a clean through-hole.
What feed should I use for drilling steel?
As a starting point with carbide drills: 0.1–0.2 mm/rev for drills under 6 mm, 0.2–0.35 mm/rev for 6–16 mm, adjusted for material hardness and coolant. HSS drills run at roughly half these values.
What is the difference between 118° and 135° drill points?
118° points suit softer materials and general work; 135° split points self-center, need less thrust and suit harder materials and CNC drilling without a center drill.