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The Rockwell Hardness High Pressure Injection Pump Number Is Different

Unlike height, weight, and width, hardness is not a fundamental property of metal. Hardness is most closely related to tensile strength and is a reliable indicator of ductility and wear resistance. The principle of any hardness testing method is to force an indentor (penetrator) into a material sample under a specific load at a controlled rate and then measure the dimensions (depth or surface area) of the indentation-High Pressure Injection Pump. Unlike length, mass, or time which have exact measures, hardness testing is a comparative measure: accurate testing results can only be achieved with calibrated machines and previous test results taken from a material of known hardness.

In metallurgy, the hardness of a material depends on a combination of yield strength, tensile strength, and modulus of elasticity – the stiffness of a material and its ability to resist deformation under applied force. It is measured by indenting a small sample piece of material without destroying it.

ROCKWELL HARDNESS TEST
The Rockwell hardness tester is essentially a machine that measures hardness by determining the depth of penetration of a penetrator into the specimen under certain fixed conditions of test. The penetrator may be either a steel ball or a diamond spheroconical penetrator. The hardness number is related to the depth of the indentation and the higher the number, the harder the material. A minor load of 10 kgf is first applied, causing an initial penetration. The dial is set at zero on the blackfigure scale, and the major load is applied. This major load is customarily 60 kgf or 100 kgf when a steel ball is used as a penetrator, but other loads may be used when necessary. The ball penetrator is 1/16" in diameter normally, but other penetrators of larger diameter, such as 1/8", may be employed for soft metals. When a diamond spheroconical penetrator is employed, the load is usually 150 kgf. Experience decides the best combination of load and penetrator for use. After the major load is applied and removed, according to standard procedure, the reading is taken while the minor load is still applied.
HOW A ROCKWELL TEST IS PERFORMED
The Rockwell Hardness Number is the difference between two controlled indentations superimposed on each other.

The first indentation is made by a minor load applied to a steel ball or diamond penetrator. Then, without moving the penetrator, a major load is applied at a precisely controlled rate.

The hardness determination is made by measuring the additional indentation made by the second major force. The scale is proportionally inverse, so that the higher the number, the shallower the indentations, therefore the harder the material.

In the Regular (R) Rockwell Scale the minor load is 10 kilograms of force (kgf) and the major load is 60, 100, or 150 kgf. In the Superficial (S) Rockwell Scale the minor load is 3 kgf and the major load is 15, 30, or 45 kgf-Injection Pump Machine.

To ensure accuracy, the major load is applied with precise control and the penetrators are manufactured to exact tolerances. Each point on the R hardness scale represents 0.00008" and 0.00004" on the S hardness scale, making the precision and control of these tests readily apparent.

Created: Jan 11 · Admin: boyuwaterproof

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