Metal hardness measurement: what is the difference between the UCI and Leeb methods?Correct measurement of metal hardness is essential for product quality assurance and for the control of input and output materials. In practice, two portable methods are most commonly encountered: the UCI (Ultrasonic Contact Impedance) and the Leeb. Both have advantages and disadvantages and are suitable for different types of measurements.
New: We have just launched our new ultrasonic hardness tester UH-300, which offers high accuracy for UCI measurements, simple operation and a robust design for industrial use at a very reasonable price. The UH-300 hardness tester is the ideal choice for anyone looking for a quality and reliable device for accurate hardness measurement!
UCI hardness tester - accurate hardness measurement even on thin materials
The UCI method uses ultrasound and a diamond tip that is pressed into the surface of the material (equivalent to the Vickers method). The change in resonance on contact with the material is used to calculate the hardness. This method is ideal for precise hardness measurement of small parts, hardened layers and thin-walled parts.
Advantages of UCI measurement:
• High accuracy comparable to laboratory methods (e.g. Vickers)
• Suitable for measuring hardened layers and small parts
• Minimal measurement footprint - ideal for finished products
• Can be measured in any position (independent of direction)
Disadvantages:
• Requires a smooth, preferably polished surface
• Higher demands on accuracy and operator experience
• Purchase price tends to be higher - but the new UH-300 delivers excellent value for money
Leeb hardness tester - fast measurement on large parts
The dynamic Leeb method is ideal for measuring the hardness of large and heavy metal parts. It works on the principle of measuring the reflection of a metal body that is shot against the surface to be measured.
Advantages of Leeb measurement:
• Fast and easy hardness measurement even in challenging conditions
• Suitable for castings, forgings and other bulky components
• Reduced surface preparation requirements
• Easy operation and calibration of the instrument
Disadvantages:
• Less accurate method for thin or small parts (in cases of really small and thin parts this method is not applicable)
• Greater plastic deformation - larger measurement footprint
• Results may be affected by the direction of measurement (gravity)
Which hardness tester to choose - UCI or Leeb?
The decision depends on the type of material to be measured and the accuracy requirements. If:
- You need accurate measurement of small or surface hardened parts → choose a UCI hardness tester, ideally our new UH-300.
- You are measuring large pieces, castings or need a quick field check → a Leeb hardness tester, such as our proven OH-120 or TH-130 hardness tester, is more suitable.
Still not sure which method to choose? Contact us - we will be happy to advise you and recommend the most suitable solution for your specific needs.
