Information
This calculator computes the length of the point of a drill bit based on its diameter and point angle.
Common drill point angles are 118° for general-purpose drilling and 135° for harder materials.
The point depth is the distance from the tip of the drill to where the full diameter is reached.
Enter drill diameter and point angle to calculate
More Information
What is Drill Point Depth?
Drill point depth refers to the distance from the tip of a drill bit to the point where the cutting edges reach their full diameter. This measurement is critical in machining operations to accurately plan drilling operations and ensure proper hole depths.
The drill point depth depends on two primary factors: the drill's diameter and its point angle. Mathematically, it is expressed as:
Where:
Depth = Point depth of the drill
Diameter = Full diameter of the drill bit
Angle = Point angle of the drill bit in degrees
Common Drill Point Angles
118° - Standard Point
The most common point angle for general-purpose drilling in a wide variety of materials. Good balance between cutting efficiency and point strength.
135° - Flat Point
Used for harder materials like stainless steel. The flatter angle provides better heat dissipation and reduces walking on hard surfaces.
90° - Screw Machine Point
Used for non-ferrous materials like brass and aluminum. The sharper point allows for easier penetration and chip evacuation.
Practical Applications
Understanding drill point depth is important for:
- CNC programming to accurately calculate total drilling depth
- Creating blind holes of precise depth
- Setting up stops on drill presses
- Avoiding breakthrough when drilling thin materials
- Calculating material removal rates
- Determining when to use spot drills or center drills