Minor Diameter Of External Thread Given Height Of Fundamental Triangle Calculator

Formula Used:

\[ Minor Diameter of External Thread = Major Diameter of External Thread - \left(\frac{17}{12} \times Height of Fundamental Triangle\right) \] \[ d_c = d - \left(\frac{17}{12} \times H\right) \]

Minor Diameter of External Thread:

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1. What is Minor Diameter of External Thread?

The Minor Diameter of External Thread is the diameter of the imaginary co-axial cylinder that just touches the base of an external thread. It represents the smallest diameter of the threaded portion.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ Minor Diameter = Major Diameter - \left(\frac{17}{12} \times Height of Fundamental Triangle\right) \]

Where:

\( Major Diameter \) — The largest diameter of the external thread (m)
\( Height of Fundamental Triangle \) — The height of the thread when the profile is extended to a sharp vee form (m)
\( \frac{17}{12} \) — Constant factor derived from thread geometry standards

Explanation: This formula calculates the minor diameter by subtracting a specific fraction of the fundamental triangle height from the major diameter.

3. Importance of Minor Diameter Calculation

Details: Accurate calculation of minor diameter is crucial for thread design, manufacturing tolerances, and ensuring proper thread engagement and strength in mechanical assemblies.

4. Using the Calculator

Tips: Enter major diameter and height of fundamental triangle in meters. Both values must be positive numbers. The calculator will compute the minor diameter of the external thread.

5. Frequently Asked Questions (FAQ)

Q1: What is the significance of the 17/12 factor?
A: The 17/12 factor is derived from standard thread geometry formulas and represents the relationship between thread height and minor diameter reduction.

Q2: How accurate is this calculation?
A: This calculation provides theoretical values based on standard thread geometry. Actual manufacturing tolerances may vary slightly.

Q3: Can this formula be used for all thread types?
A: This specific formula is designed for standard external threads. Different thread profiles may require different calculation methods.

Q4: What units should be used for input values?
A: The calculator uses meters for both input values, but you can use any consistent unit system as long as both inputs use the same units.

Q5: Why is minor diameter important in thread design?
A: Minor diameter determines the core strength of the threaded component and affects the thread's load-bearing capacity and fatigue resistance.