Rockwell Calculator

Understanding Rockwell Hardness and Using a Rockwell Calculator

Introduction

Rockwell hardness calculator is a tool used for testing and hardness testing is a widely used method for determining the hardness of materials. It measures the depth of penetration of an indenter under a large load compared to the penetration made by a preload. The Rockwell hardness number is then calculated based on these measurements.

Rockwell Hardness Scales

There are several Rockwell hardness scales, each suitable for different types of materials. The most common scales are Rockwell A (RcA), Rockwell B (RcB), and Rockwell C (RcC). The choice of scale depends on the hardness of the material being tested.

• Rockwell A (RcA): Used for softer materials like plastics and rubber.
• Rockwell B (RcB): Commonly used for softer metals and alloys.
• Rockwell C (RcC): Applied to harder materials, such as hardened steel.

The Rockwell Hardness Test Process

1. Preparation:
   • The test material should be properly prepared and mounted.
   • A diamond or ball indenter is used based on the material and hardness scale.
2. Preload:
   • A minor load is applied to set the indenter on the material’s surface.
3. Main Load:
   • A major load is applied for a specific duration.
   • The indenter penetrates the material, and the depth of penetration is measured.
4. Unloading:
   • The main load is removed, and a minor load is reapplied.
5. Measurement:
   • The remaining depth of penetration is measured, and the Rockwell hardness number is determined.

Rockwell Hardness Formula

The Rockwell hardness number (RHN) is calculated using the following formula:

RHN = 100− ​htest ​− hinitial​ / hpreload

where:

• ℎtesthtest​ is the depth of penetration after the main load is applied.
• ℎinitialhinitial​ is the depth of penetration after the preload.
• ℎpreloadhpreload​ is the depth of penetration during the preload.

Using a Rockwell Calculator

To calculate Rockwell hardness manually, you need the depth of penetration measurements obtained during the test. The Rockwell Calculator simplifies this process, allowing you to input the values and get the hardness number without manual calculations.

Steps for Using the Rockwell Calculator:

1. Enter Depth of Penetration:
   • Input the values for ℎtesthtest​, ℎinitialhinitial​, and ℎpreloadhpreload​ into the calculator.
2. Select the Hardness Scale:
   • Choose the appropriate Rockwell hardness scale (A, B, or C).
3. Calculate:
   • Click the “Calculate” button to obtain the Rockwell hardness number.
4. Interpret Results:
   • The calculator provides the Rockwell hardness number, helping you assess the material’s hardness.

Wrapping it up

Understanding Rockwell hardness and using a Rockwell calculator is essential for materials testing and quality control in various industries. By following standardized procedures and using the Rockwell hardness formula, professionals can obtain accurate hardness measurements for a wide range of materials.