드릴 포인트 팁 길이 및 관통 여유 계산기
118°, 135° 및 특수 각도 드릴의 선단 높이, 막힌 구멍 및 관통 홀 여유 깊이 계산.
Point & Depth Parameters
Calculate drill point offset, tip length, and full machine depth
l = (D / 2) / tan(θ / 2)For a standard 118° drill, point length is approximately 0.300 × Diameter. For 135° split points, it is approximately 0.207 × Diameter.
The Mathematics of Drill Point Tip Length
When programming CNC hole drilling or setting manual depth stops, understanding the difference between the cylindrical hole depth (the usable flat diameter) and the total drill tip travel is critical. If a print calls for a 1.000" blind hole, drilling only to 1.000" Z-depth results in an undersized cylindrical depth because the conical point has not completed its diameter!
118° Standard Point Angle
The traditional general-purpose drill point. Well-suited for mild steels, aluminum, brass, and plastics.
Example: 1/2" (12.7mm) drill has a 0.150" (3.81mm) tip length.
135° Split Point Angle
Flatter cone with web thinning. Eliminates chisel edge wandering, penetrates tough stainless steels, and reduces breakthrough burrs.
Example: 1/2" (12.7mm) drill has a 0.103" (2.63mm) tip length.