Feed and Speed Calculator Drilling

Drilling Speed Formula:

\[ \text{Speed (rpm)} = \frac{\text{CS (m/min)} \times 4}{\text{D (in)}} \]

Speed:

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1. What is Drilling Speed Calculation?

The drilling speed calculation determines the optimal rotational speed (RPM) for a drill bit based on the cutting speed of the material and the diameter of the drill bit. This ensures efficient material removal while prolonging tool life.

2. How Does the Calculator Work?

The calculator uses the drilling speed formula:

\[ \text{Speed (rpm)} = \frac{\text{CS (m/min)} \times 4}{\text{D (in)}} \]

Where:

\( CS \) — Cutting speed of the material (meters per minute)
\( D \) — Diameter of the drill bit (inches)
4 — Conversion factor (combining unit conversions and π)

Explanation: The formula converts the linear cutting speed to rotational speed while accounting for different measurement units (meters to inches).

3. Importance of Speed Calculation

Details: Proper speed calculation prevents tool damage, ensures efficient cutting, and improves hole quality. Too high speed causes overheating, while too low speed reduces productivity.

4. Using the Calculator

Tips: Enter the material's recommended cutting speed in m/min and the drill bit diameter in inches. Both values must be greater than zero.

5. Frequently Asked Questions (FAQ)

Q1: Where can I find cutting speed values for different materials?
A: Cutting speed tables are available in machining handbooks or from tool manufacturers. Common values: Aluminum (60-300 m/min), Steel (30-60 m/min), Stainless Steel (10-40 m/min).

Q2: Why is diameter in inches while speed is metric?
A: This reflects common industry practice where drill sizes are often in inches while cutting speeds are in metric units. The formula includes the necessary conversion.

Q3: How does this relate to feed rate?
A: Feed rate (mm/rev or in/rev) is separate from speed and depends on factors like material and drill bit type. Both must be optimized for best results.

Q4: Should I adjust for different drill materials?
A: Yes, HSS and carbide drills can use different cutting speeds. Always consult manufacturer recommendations for specific tools.

Q5: What about very small or large diameters?
A: Extremely small diameters may require higher speeds than calculated, while large diameters may need reduction to stay within machine capabilities.