1. What is the Major Diameter of Internal Thread?

The Major Diameter of Internal Thread is defined as the sum of minor diameter of the internal thread and 1.25 times the value of the height of the fundamental triangle. It represents the largest diameter of the internal thread profile.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( D \) — Major Diameter of Internal Thread (m)
• \( D_p \) — Pitch Diameter of Internal Thread (m)
• \( H \) — Height of Fundamental Triangle (m)

Explanation: The formula calculates the major diameter by adding 75% of the fundamental triangle height to the pitch diameter of the internal thread.

3. Importance of Major Diameter Calculation

Details: Accurate calculation of major diameter is crucial for proper thread design, manufacturing, and ensuring compatibility with mating external threads in mechanical assemblies.

4. Using the Calculator

Tips: Enter pitch diameter and height of fundamental triangle in meters. Both values must be valid non-negative numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is the relationship between major diameter and pitch diameter?
A: The major diameter is larger than the pitch diameter, with the difference being related to the thread height and form.

Q2: Why is the height of fundamental triangle important in thread calculations?
A: The fundamental triangle height determines the basic thread form and is used to calculate various thread dimensions including major and minor diameters.

Q3: Can this formula be used for all thread types?
A: This specific formula is designed for standard thread forms. Special thread forms may require different calculations.

Q4: How accurate is this calculation method?
A: The formula provides theoretical values based on standard thread geometry. Actual manufactured threads may have tolerances applied.

Q5: What units should be used for input values?
A: The calculator uses meters as the standard unit, but consistent units must be used for all inputs.