Chinese plastics manufacturer relies on ZwickRoell hardness testing technology

Chinese plastics manufacturer Suzhou Subway Polymer is a leading supplier to the Chinese automotive industry. In a further expansion of the factory's testing laboratory capacity the company has opted for a ZwickRoell ZHR hardness tester.

The company will be using the ZwickRoell ZHR8150CLK hardness tester in connection with its future research activities. The tester can be used for more than thirty different depth measurement applications, including Rockwell and ball indentation.


During determination of ball-indentation hardness to ISO 2039-1 a spherical indenter 5 mm in diameter is pressed into the plastic under test, at a constant test load. The standard specifies a range of test loads, limiting the indentation depth to a range between 0.15 mm and 0.345 mm. The high test loads and large indentation allow measurement over a large test area, enabling strong averaging of the measured value.

Rockwell hardness tests to ISO 2039-2 or ASTM D785 can also be performed with this hardness tester. In contrast to ball-indentation hardness, in which the indentation depth is measured under load, indentation depth measurement using the Rockwell method takes place at a defined pre-load. Various indenters are available in line with the Rockwell scales.

The straightforward operation of the tester and well-established after-sales service in China were the key factors in the choice of ZwickRoell as a supplier. High-precision calibration of direct force and indentation depth guarantee excellent test-result reproducibility.