1. What is RPM to Surface Speed Conversion?

Definition: This calculator converts rotational speed (RPM) to linear surface speed (SFM) for rotating tools or workpieces.

Purpose: Essential for machining operations to determine proper cutting speeds for different materials and tooling.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( SFM \) — Surface Feet per Minute
• \( RPM \) — Revolutions Per Minute
• \( D \) — Diameter in inches
• \( \pi \) — Pi (approximately 3.1416)

Explanation: The formula calculates how many feet the surface of a rotating object travels in one minute.

3. Importance of Surface Speed Calculation

Details: Proper SFM ensures optimal tool life, material removal rates, and surface finish in machining operations.

4. Using the Calculator

Tips: Enter the RPM of your spindle and the diameter of your tool or workpiece in inches. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: Why is surface speed important in machining?
A: Different materials require specific surface speeds for efficient cutting without excessive tool wear.

Q2: How does diameter affect surface speed?
A: Larger diameters produce higher surface speeds at the same RPM due to greater circumference.

Q3: What's a typical SFM range?
A: Varies by material: 100-300 SFM for steel, 300-600 for aluminum, 50-150 for titanium.

Q4: Can I use this for both tools and workpieces?
A: Yes, it works for either rotating tools or rotating workpieces.

Q5: Why divide by 12 in the formula?
A: This converts the result from inches per minute to feet per minute (12 inches = 1 foot).