Rockwell and Vickers Hardness Testing Scales

 Hardness testing plays a crucial role in manufacturing, quality control, and material selection across industries like aerospace, automotive, energy, and heavy machinery. Among the various methods available, Rockwell and Vickers hardness testing using hardness testers are two of the most widely used. Each serves a distinct purpose and is suited for different types of materials and applications.

In this guide, we’ll break down how these hardness scales work, when to use each, and provide detailed hardness conversion tables for easy reference. Whether you’re testing hardened steel, soft metals, or thin coatings, understanding these scales can help you make informed decisions about material performance and durability.

What is Hardness Testing?

Hardness testing measures a material’s resistance to deformation, particularly indentation. It helps engineers and manufacturers determine how well a material can withstand wear, pressure, and stress over time.

The results of hardness tests influence decisions in:

• Material selection – ensuring metals and alloys meet strength requirements.
• Quality control – verifying consistency in production.
• Predictive maintenance – identifying early signs of wear in components.

Two of the most widely used hardness testing methods are Rockwell Hardness (HR) and Vickers Hardness (HV).

Rockwell Hardness Scale (HR)

The Rockwell Hardness Test is one of the most common hardness tests used in industrial applications. It measures the depth of penetration of an indenter under a major load. The test is quick, requires minimal sample preparation, and is widely used for metals and polymers.

How Rockwell Hardness Testing Works

1. A minor load (usually 10 kgf) is applied to the material using an indenter (either a steel ball or a diamond cone).
2. A major load (which varies based on material type) is applied and held for a set time.
3. The depth of penetration is measured, and the hardness value is displayed directly on the machine.

The Rockwell test has multiple scales, each suited for different materials. The two most common are:

• HRC (Rockwell C) – Used for hardened steel and hard alloys.
• HRB (Rockwell B) – Used for softer metals like aluminum, brass, and annealed copper.

Rockwell Hardness Scale Chart

Vickers Hardness Scale (HV)

Unlike the Rockwell test, the Vickers Hardness Test measures the size of an indentation left by a diamond pyramid-shaped indenter rather than penetration depth. It is commonly used for thin materials, coatings, and microhardness testing.

How Vickers Hardness Testing Works

1. A diamond pyramid-shaped indenter is pressed into the material under a specific load (ranging from a few grams to 100 kgf).
2. The indentation’s diagonal lengths are measured using a microscope.
3. The Vickers Hardness Number (VHN or HV) is calculated based on the indentation size and applied force.

Why Use Vickers Hardness Testing?

• High accuracy – Ideal for very thin materials and microhardness applications.
• Universal – Can test a wide range of materials, including very soft and very hard metals.
• Non-destructive – Leaves a very small indentation compared to Rockwell testing.

Vickers hardness is widely used in:

• Aerospace – Testing jet engine coatings and thin metal components.
• Medical – Measuring the hardness of titanium implants.
• Electronics – Assessing micro-components and solder joints.

Vickers Hardness Scale Chart

Below is a reference table showing Vickers hardness values for various materials and their approximate Rockwell equivalents:

Vickers Hardness Scale Table

Rockwell vs. Vickers: Key Differences and When to Use Each

When to Use Rockwell Hardness Testing

• If you need a fast, direct reading without extra calculations.
• When testing bulk materials like steel, brass, or aluminum.
• If you are testing materials in a production line where quick results are needed.

When to Use Vickers Hardness Testing

• If you need very precise measurements for thin materials.
• When testing microhardness, such as small components or coatings.
• If you are working with soft metals like gold, copper, or delicate alloys.

Choosing the Right Hardness Tester for Your Needs

If your industry requires frequent hardness testing, choosing the right method is essential for accuracy and efficiency. Here’s what to consider:

1. Material Type – Are you testing bulk materials or thin coatings?
2. Testing Speed – Do you need instant readings (Rockwell) or high precision (Vickers)?
3. Industry Standards – Different industries require different hardness tests for compliance.
4. Cost & Convenience – Rockwell testers are generally faster and more affordable, while Vickers testers provide higher precision but require additional measurement tools.

METSUCO offers a range of Rockwell and Vickers hardness testers, ensuring you have the right equipment for your specific needs.

Conclusion

Hardness testing is an essential part of material selection and quality control. Rockwell testing is great for fast, large-scale material testing, while Vickers testing is ideal for precision and thin materials. Both play critical roles in industries like automotive, aerospace, and manufacturing.

Choosing the right hardness testing method can save time, reduce costs, and improve product reliability. If you’re looking for accurate and reliable hardness testers, explore METSUCO’s selection and find the perfect fit for your industry needs