Sample Preparation Room

Mechanical tests of mechanical properties of structural metal materials, concrete reinforcements, weld joints and also plastics and textile belts are carried out in the mechanical testing laboratory. Degradation of used metal materials is also determined here. If samples prepared according to the required standards are not available, qualified personnel can provide the preparation of these samples.

Tests of mechanical properties are carried out at ambient, elevated and low temperatures, depending on the further use of the material. The tests are carried out according to Czech, European, international and other foreign standards (ČSN, EN, ISO, ASME, DIN, GOST, etc.).

Tests carried out:

The tensile test is performed on metal, plastic and textile belts. It determines the behaviour of the material under the action of a static, calmly increasing force. It can be performed at the ambient temperature, at both higher and lower temperatures (up to -60°C). The tensile strength, the upper and lower yield points, elongation and contraction are evaluated during the test. The test will provide some of the basic values required for the calculation of the structural elements and the selection of the appropriate material. A validated graphic record can document the course of the test. The test can be carried out also on concrete steel reinforcements.

The creep testing at high temperature is an important feature of metallic materials used at higher temperatures. This is a long-term tensile test, that determines the tensile creep limit at a given higher temperature (elongation, contraction, time to break), calculated from the measured creep curve. The test can be performed both for shorter and longer time intervals.

The bend test (steel, cast iron and metal and plastic welds) is used to evaluate the plasticity of the material according to the bend angle of the sample and the ability to resist cracking at the bending point. The test is carried out by placing the test piece on two supports and by loading gradually and continuously on the centre of the weld. The bend angle is measured until it cracks or is permanently bent. The test is predominantly used to determine the brittleness of the grey cast alloy and the technological tests of the quality of metal and plastic welds.

The impact bend test enables the assessment of the material in terms of its toughness, i.e.  the ability of the material to plastically deform without cracking at ambient, elevated and low temperatures. The impact bend test involves striking a standard specimen with a controlled weight pendulum. The amount of energy absorbed in fracturing the test piece is measured. The heat-treated steels, welds and non-ferrous metals are being evaluated by this test.

Shear strength test (steel, cast iron, welds), determines the maximum shear strength for metallurgical products with a circular cross section. The specimen is placed into a shear device and the upper part is loaded with continuously increasing pressure until the surface of the specimen is damaged. The result of the test is determination of the shear strength. In addition to a traditional use, this test is also performed for concrete steel reinforcements.

The heading test (steel, cast iron, welds) is used to determine the surface cleanliness of materials intended for the production of rivets, nails, etc. The material is suitable if no cracks occurred during the heading test of the specimen.

The hardness tests reflect the quality of the material, e.g. the condition of the structure after heat treatment. Vickers (HV), Brinell (HBS, HBW) and Rockwell (HRA to HRK) hardness tests are carried out depending on the design and shape of the specimen.

Technological tests of tubes:

Tests by flattening and flaring tests are used to check the mouldability of tubes, in particular cold drawn, which are suitable provided the samples have no visible cracks on the surface.

The tensile test is carried out in the same way as for other metallic materials. However, samples prepared from the tubes may be used for the test, or the test can be performed directly on tube offcuts with a diameter up to 60 mm when inserting a mandrel into the tube.

Sample preparation room:

The testing laboratory itself prepares test pieces, including the test pieces for ASME (preparation of samples is not subject to accreditation). We now have at our disposal a belt gravity saw from the Czech manufacturer PILEDA, which allows cutting oversized samples (logs up to 360 mm and others with maximum dimensions of 360 mm x 500 mm).