HARDNESS TESTING ACADEMY

Page Scope

The ATI Hardness Testing Academy is a collection of technical articles designed to provide a clear and structured understanding of hardness testing methods, standards and applications. This section includes both practical guides and in-depth technical resources, covering Rockwell, Brinell, Vickers, Knoop and related testing principles in accordance with ASTM and ISO standards.

Whether you are working in production, laboratory testing, quality control, incoming inspection, heat treatment verification or auditing, these resources are intended to support correct test execution, method selection and result interpretation.

Explore the articles below to deepen your knowledge and improve the reliability, repeatability and consistency of your hardness testing processes.

Table of contents

• General hardness testing guides
• Rockwell hardness testing
• Brinell hardness testing
• Vickers and Knoop hardness testing
• Calibration, standards and metrology
• From theory to equipment

General hardness testing guides

These articles provide a broad introduction to hardness testing, including the main methods, industrial applications and practical criteria for selecting the most suitable test according to material type, geometry, surface condition, thickness and testing requirements.

• Hardness Testing
  General overview of hardness testing methods, applications, standards and types of hardness testers.
• Methods overview
  Main differences and typical use of Rockwell, Brinell and Vickers hardness testing methods.
• How to Choose the Right Hardness Tester
  Practical guidelines to select the correct hardness tester according to material, application and testing method.

Rockwell hardness testing

This section collects practical and theoretical resources dedicated to Rockwell and Superficial Rockwell hardness testing, including test principles, scale selection, minimum thickness, repeatability, common errors and standards-oriented technical guidance.

• Rockwell Hardness Testing
  Practical guide to Rockwell hardness testing, scale selection, specimen preparation, valid results and common industrial applications.
  what it is | scale selection | test conditions | equipment.
• The Rockwell Hardness Test Theory
  In-depth technical guide to ASTM E18 and ISO 6508, including test cycle, terminology, thickness, repeatability and error.
  Rockwell C | Rockwell B | minimum thickness | repeatability and error | terminology and tips.

Brinell hardness testing

This section is dedicated to Brinell hardness testing and its typical use on castings, forgings, large sections and materials with coarse or non-uniform microstructures. Brinell is often selected when a larger indentation is useful to obtain a more representative average hardness value over a wider material area.

• Brinell Hardness Testing
  Practical guide to Brinell hardness testing, ball and force selection, indentation measurement, specimen requirements and common industrial applications.
  what it is | how it works | test conditions | applications | equipment.
• The Brinell Hardness Test Theory
  In-depth technical guide to ASTM E10 and ISO 6506, including Brinell test principle, force-diameter ratio, indentation measurement, minimum thickness, repeatability and error.
  test principle | application scales | minimum thickness | repeatability and error | terminology and tips.

Vickers and Knoop hardness testing

This section covers Vickers and Knoop hardness testing, including optical indentation measurement, diagonal reading, microhardness testing, thin materials, coatings, case hardness depth profiles, weld analysis and metallographic applications.

Vickers and Knoop methods are especially useful when the test area is small, the layer is thin, the indentation must be measured under magnification or a hardness profile must be performed across a polished cross-section.

• Vickers Hardness Testing
  Practical guide to Vickers hardness testing, force selection, sample preparation, optical measurement, microhardness applications and common testing errors.
  what it is | how it works | sample preparation | Case Depth CHD | equipment.
• The Vickers and Knoop Hardness Test Theory
  In-depth technical guide to ASTM E384, ASTM E92, ISO 6507 and ISO 4545, including indenter geometry, formulas, test forces, indentation spacing, repeatability and error.
  Vickers vs Knoop | Vickers principle | Knoop principle | test forces | repeatability and error | terminology and tips.