Simple and economical device for determining Brinell hardness and tensile strength of structural and tool steel, dies, molds, forgings, railway materials, beams, sheets, pipes, cast steel, and various steel parts, as well as Brinell hardness of bronze castings, aluminum castings, brass, copper, gray cast iron, and hard cast iron.
The device allows testing by impact using a hammer at the workplace, in workshops, during assemblies, and other locations. Brinell hardness and tensile strength can be directly obtained from tables.
Application:
A hardened steel ball with a diameter of 10 mm is placed between the object to be tested and a calibrated steel rod of specific tensile strength (reference rod). A single powerful blow with a hammer creates an indentation simultaneously in the reference rod and on the test piece. The diameters of both indentations are carefully measured using a measuring loupe provided with the device. Based on these measurements, the Brinell hardness and strength of the specimen can be determined directly from the numerical table. If a measuring microscope is available, the indentation diameters can be measured much more accurately. In the standard version of the POLDI hardness tester with a reference rod made of steel with a strength of 70 kg/mm², the maximum deviation of the ball pressure strength from the actual tensile strength of steel with a strength of 50 – 100 kg/mm² is ± 3%, for softer iron and steel grades and for steel with a strength of 100 – 150 kg/mm² (e.g., hardened, tempered, and high-alloy steels) ± 5%. With a strength of 150 – 200 kg/mm², the inaccuracy may be slightly greater under certain circumstances. The POLDI hardness tester, like Brinell's ball pressure tester, is applicable to all forgeable iron and steel grades, except austenitic steels such as 25% nickel steel, 14% manganese steel, rust-resistant chromium-nickel steel, non-magnetic steel, etc. Individual calibrated steel pieces are sufficient for approximately 40 tests.
Delivery in a wooden case including reference rod, loupe, and hardness value table
