Bolt Root Area Calculator

How to calculate the root area of a bolt? Here is how you can, enter your specific like, the Nominal Diameter or Thread Pitch into the calculator to calculate the Root Area of a bolt.

Bolt Root Area Calculator

Enter any 2 values to calculate the missing variable

Nominal Diameter

mm in

Thread Pitch

mm in

Root Area

mm² in²

Calculate Reset

Show Calculation Steps ▼

What is the Bolt Root Area?

The Bolt Root Area is the cross-sectional area of a bolt at its root, which is crucial for understanding its strength.

How to Use the Calculator

The calculator offers both Basic and Advanced modes.

1. Basic Calculator

1. Enter Nominal Diameter (mm): Type the diameter of the bolt. Example: 10.
2. Enter Thread Pitch (mm): Input the pitch size. Example: 1.5.
3. Calculate Root Area (mm²): Click “Calculate” to find the unknown value.

2. Advanced Calculator

1. Enter Nominal Diameter (mm): Provide the diameter. Example: 12.
2. Enter Thread Pitch (mm): Provide the pitch. Example: 2.
3. Calculate Stress Area (mm²): Click “Calculate” to get the stress area.

Formula

The formula to calculate the bolt root area is:

$A=\pi \times {\left(\frac{D_r}{2}\right)}^2$

Variables

Variable	Description
A	Root Area (mm²)
$D_r$	Root Diameter (mm)

How To Calculate Root Area Of The Bot

Example 1

Input: 

• Diameter = 10 mm,
• Pitch = 1.5 mm

Calculation:

1. Calculate the root diameter:

$D_r=10-(1.226869\times 1.5)=8.159$

2. Use the formula: 

$A=\pi \times {\left(\frac{8.159}{2}\right)}^2$

3: Divide root diameter by 2:

$4.0795$

2: Square the result:

$16.640$

3: Multiply by π:

$52.2869$

Result: Root Area = 52.2869 mm²

Example 2

Input: 

• Diameter = 12 mm,
• Pitch = 2 mm

Calculation:

1. Calculate the root diameter: 

$D_r=12-(1.226869\times 2)=9.546$

2. Use the formula: 

$A=\pi \times {\left(\frac{9.546}{2}\right)}^2$

3: Divide root diameter by 2:

$4.773$

2: Square the result:

$22.784$

3: Multiply by π:

$71.5846$

Result: Root Area = 71.5846 mm²

Our calculator simplifies the process of finding the bolt root area, ensuring accurate and quick results. Use it to enhance your understanding and calculations.