Preliminary test force in hardness testing

Hardness test preload is a small initial force in hardness testing methods like Rockwell, which minimizes surface roughness effects and defines the zero position for depth measurement.

Physical-Chemical Mechanism

The preload removes surface noise and ensures that the measuring point is consistent. It does not affect the actual hardness of the material.

Metallurgical Relevance & Welding Risks

Too high a preload can damage the material or produce incorrect results. Too low a preload leads to inaccurate measurements and increases the uncertainty of hardness determination.

Workshop Practice & Procedures

Always use the recommended preload for the specific hardness testing method. For Rockwell, this is typically 10 kgf (approx. 98.1 N). Make sure the contact between the specimen and the indenter is smooth and without stress.

MetallurgieSchweißtechnik