Method
Equation
P = D / (2 tan(θ/2))Tip depth = full-diameter depth + P + breakthroughGeometry
Drill Point Depth Calculator — Full Diameter Hole
Choose blind or through, select a stock drill and common 118°, 135° or 140° point. Dimvo adds the conical point allowance and returns the programmed tip depth from Z0.
Decimal points and decimal commas are accepted.
Stock drill diametersmm
Programmed tip depth
Depth from top
23.0043 mm
Program coordinate
Z-23.0043
Full-diameter depth
20 mm
Point allowance
3.0043 mm
20 + 3.004 = 23.004 mm
The point allowance assumes an ideal conical drill. Confirm the actual drill geometry. Tip breakthrough alone does not mean the full hole diameter has passed through the material.
Quick use
How to use this calculator
- Choose blind or through hole and enter the required full-diameter depth.
- Pick the drill diameter and point style; use a custom angle only when needed.
- Use the returned tip coordinate and verify the actual drill geometry and safe breakthrough.
Limits
Assumptions
- Symmetric conical point
- Included angle entered in degrees
- Web and chisel geometry excluded
Provenance
Independent calculation
Generated from the displayed equation and user inputs. This page does not reproduce a standard or third-party table.
Common questions
Frequently asked questions
Why is programmed drill depth longer than hole depth?
A twist drill has a conical point. The centre reaches depth before the full diameter, so the point length must be added when the drawing depth refers to full diameter.
Does this include the drill's chisel edge?
No. The model treats the point as a symmetric cone and excludes web thinning and chisel-edge geometry.