Leeb Hardness Testing Method

Leeb hardness testing is a portable method used to inspect metal hardness. It was developed in 1975 by Leeb and Brandestini, and is now part of Proceq (Switzerland).

Leeb Hardness Testing Principle

Leeb testing is based on rebound measurement. A rod-shaped impact body contains an indenter that a fixed spring drives into the test surface. The indenter leaves an impression and loses energy according to the material hardness. This energy loss is determined by measuring indenter velocities Vi and Vr before and after impact.

A magnet inside the impact body generates current in a coil. The current is proportional to the indenter velocity. The signal is processed to provide a hardness value.

Leeb Hardness Measurement Unit

• Unit: HL (HLC, HLA, HLD, etc.)
• HL can be converted to common hardness scales such as HV, HB, HRB, HRC, HRA, and material tensile strength in accordance with standards.

Advantages of Leeb Hardness Testers

• Measures hardness of iron, steel, cast iron, and various alloys.
• Compact design suits field testing and large workpieces that cannot be measured on bench-top testers.
• A range of probes suits applications such as gears, rolling shafts, crankshafts, flanges, and engine housings.
• Portable, lightweight, and compact for on-site testing of large objects.
• Fast inspection and easy operation.
• Lower cost than other methods.

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