1. What is the Internal Thread Calculator?

The Internal Thread Calculator computes the minor diameter for internal metric threads using the standard formula. This measurement is crucial for proper thread design and manufacturing.

2. How Does the Calculator Work?

The calculator uses the standard internal thread formula:

Where:

• Major Diameter — The largest diameter of the thread (mm)
• Pitch — The distance between thread crests (mm)
• 1.0825 — Standard coefficient for metric threads

Explanation: The formula accounts for the standard thread profile geometry in metric threads.

3. Importance of Minor Diameter Calculation

Details: Accurate minor diameter calculation ensures proper thread engagement, strength, and compatibility with mating parts.

4. Using the Calculator

Tips: Enter major diameter and pitch in millimeters. Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is the difference between major and minor diameter?
A: Major diameter is the largest diameter of the thread, while minor diameter is the smallest diameter at the root of the thread.

Q2: Is this formula specific to metric threads?
A: Yes, this formula applies specifically to standard metric (ISO) thread profiles.

Q3: What tolerance should be applied to the minor diameter?
A: Tolerances depend on the thread class fit required (e.g., 6H for general purposes). Consult thread standards for specific tolerance values.

Q4: Can this be used for internal threads in blind holes?
A: Yes, but additional considerations for thread depth and chamfer may be needed for blind holes.

Q5: How does this relate to tap drill size?
A: The minor diameter determines the appropriate tap drill size, though some clearance is typically added.