Hardness It is the ability of a metal surface to resist localized plastic deformation (such as dents, cuts, or scratches) when subjected to an external force through a test object (impact) of higher hardness. Metal hardness measurement This is the process of determining the ability of a metal surface to resist local deformation (such as dents, cuts, or scratches) under the influence of a specific external force. It is an important indicator for evaluating the durability, wear resistance, and mechanical properties of materials in manufacturing.

Classifying and comparing hardness scales helps in selecting the most suitable testing method for material properties and technical requirements. Semiki lists standards such as ASTM E10 (Brinell), ASTM E18 (Rockwell) and ASTM E92 (Vickers) It remains a core component in the metals industry.

Below is a comparison table of common hardness scales used for metals: 

Criteria	Rockwell (HR)	Brinell (HB)	Vickers (HV)	Leeb (HL)
Test probe	Diamond hat (${120}^{\circ }$120°) or steel ball	Hardened steel or tungsten ball$D=10mm$D=10mm)	Square pyramid-shaped diamond (${136}^{\circ }$136∘)	Steel ball or small diamond tip
Principle	Measure depth of the indentation	Measure area/diameter dent	Measure diagonal of the indentation	Measure velocity ratio bounce
Advantage	Fast, results are displayed directly, no optical measurement required.	Measures raw, heterogeneous materials (such as castings, forgings).	Very high accuracy, suitable for all hardness ranges and thin materials.	Mobile, capable of measuring massive metal blocks on-site.
Disadvantages	Errors may occur if the surface is not smooth or the workpiece is too thin.	Causes significant surface damage (large dents), slow measurement.	Requires extremely thorough surface preparation (polishing) and lengthy measurements.	Accuracy depends on the roughness and weight of the object being measured.
Application	Mass quality inspection, tempered steel	Castings, non-ferrous metals, unheat-treated steel	Research and testing of coatings and micro-details.	Inspect tanks and large machinery at the site.

MITUTOYO HR-210MR (963-220-10A) Rockwell metal hardness tester

Guide to choosing the appropriate scale

• If the material is thick and coarse (like cast steel): A Brinell meter should be used because its large indentation area allows for more accurate averaging.
• If you need quick results in the production line: Ladder Rockwell (HRC/HRB) It is the optimal choice due to its high level of automation.
• If the sample is very thin or has a coating: Only Vickers or Knoop (Microhardness) is the key to accurate results without completely damaging the sample.
• If the object is too large to be placed on the desktop: Use Leeb measuring instrument mobile.

Instructions for use benchtop hardness tester (Rockwell HR, Brinell HB, Vickers HV)

This type of device is commonly used in laboratories or workshops to measure small to medium-sized parts.

• Step 1: Prepare the sample surface: This is the most important step. The metal surface must be clean, flat, and smooth. With a Vickers machine, the surface needs to be polished to a mirror finish. Learn how to prepare the metal sample for testing.
• Step 2: Select the test probe and load: Depending on the material to be measured, select the appropriate test tip (diamond or steel ball) and pressure (load) on the control panel.
• Step 3: Place the sample on the machine table: Position the specimen properly, ensuring the surface to be measured is perpendicular to the test probe to avoid breaking the probe or obtaining inaccurate results.
• Step 4: Proceed with the measurement:
  • Raise the test bench until the sample is in contact with the test probe.
  • Press the Start button to allow the machine to automatically perform the pressing and holding motion.
• Step 5: Read the results: After the probe is drawn in, the result will be displayed directly on the digital screen (for Rockwell probes) or you will have to measure the size of the indentation under a microscope (for Brinell/Vickers probes).

Important notes to ensure accuracy.

• Machine calibration: Before taking measurements, a test should be performed on the affected area. Standard sample piece (Hardness Test Block) The device comes with a receipt to verify its accuracy.

YAMAMOTO HV Test Blocks Vickers HV hardness standard

• Distance between measurement points: The indentations must be spaced at least three times the diameter of the indentation to avoid affecting the previously deformed area.
• Material thickness: The thickness of the sample must be at least 10 times the depth of the indentation.

YAMAMOTO HRC Rockwell HRC hardness standard sample

Hardness testing is not just a secondary inspection step, but a crucial factor determining the quality and safety of a product.

1. Quality control of heat treatment (Heat treatment):
   In precision engineering, components such as gears, camshafts, and molds are often hardened to increase their strength. Measuring hardness (usually using the HRC scale) is the only way to confirm whether the heat treatment process has met the requirements. If it is too hard, the component is prone to brittle fracture; if it is too soft, the component will wear out quickly.
2. Ensure accurate assembly:
   Precision machine components operate with extremely small tolerances (a few micrometers). If the hardness is inconsistent or not as designed, under working pressure, the metal surface can undergo plastic deformation, altering its geometric dimensions and leading to machine jamming or system failure.
3. Optimizing the machining process:
   Knowing the exact hardness of the workpiece helps engineers choose the appropriate type. knife tools and cutting speed It's important to ensure proper hardness measurement. Using a tool that isn't hard enough to cut a very hard workpiece will chip the tool, break the drill bit, causing significant economic losses and disrupting the automated production line.
4. Predict wear resistance and lifespan:
   Hardness is directly proportional to surface wear resistance. In assemblies with relative moving parts, controlling hardness helps ensure the equipment operates reliably throughout its designed lifespan, minimizing maintenance costs for the end user.
5. Standardization and Export:
   For Vietnamese mechanical products to participate in global supply chains (such as aerospace, medical, and electric vehicles), all products must be accompanied by a certificate of inspection of their mechanical properties, including...

Rockwell Hardness Tester 150E electronic HRC hardness tester

The choice SEMIKI Measurement Equipment Co., Ltd. (SMK VN) Consulting and purchasing hardness testing equipment is one option. suitable and reliable, especially for businesses that require high technical standards from Japan.

SEMIKI is a distributor of many leading global brands of hardness testing equipment.

• Metal: We offer benchtop and handheld hardness testers from reputable manufacturers such as Mitutoyo, Future-tech, Togoshi Seiki.
• Rubber & Plastics: Distributing Shore hardness testers (Durometers) from Teclock, Asker.
• Standard accessories: We provide a full range of hardness test blocks from Yamamoto For testing and calibrating the machine.

Contact Semiki:

Website: You can find out more details and send a consultation request via Semiki.com.

Business email: [email protected]

Phone number (Hotline): +84 979 761 016.