December 2018, Vol. 18, No. 6 MANUFACTURING TECHNOLOGY ISSN 1213–2489 indexed on: http://www.scopus.com 943 Hardness Tests and Dimensional and Shape Precision Analysis of Construction and Agricul- tural Machinery Components Petra Kvasnová 1 , Martin Kučerka 1 , Dušan Hrubý 2 , Daniel Novák 1 , Viktor Novák 3 1 Matej Bel University, Faculty of Natural Sciences, Department of Mathematics, Tajovského 40, 974 01 Banská Bystrica, Slovakia. E-mail: petra.kvasnova@umb.sk, martin.kucerka@umb.sk, daniel.novak@umb.sk 2 Slovak University of Agriculture in Ntra, Faculty of Engineering, Department of Electrical Engineering, Automation and Informatics, Tr. Andreja Hlinku 2, SK949 76 Nitra, Slovakia, dusan.hruby@uniag.sk 3 Czech University of Life Sciences Prague, Faculty of Engineering, Department of Electrical Engineering and Automa- tion, Kamýcká 129, 165 21 Prague 6, Czech Republic. E-mail: novakviktor@tf.czu.cz The article deals with hardness tests and dimensional and shape precision analysis of construction and agricultural machinery components, namely with the clamping head and case of hydraulic hammer. The clamping head is made of 41 4220 class (1.7131, 16MnCr5) construction stainless steel and the case is made of 41 5130 class (1.7218, 25CrMo4) construction stainless steel. The micro hardness was measured on VICKERS LM 700 AT hardness tester, according to the national standard STN EN ISO 6507-1: this procedure includes injection of a diamond regular four-bladed pyramid with a 136° peak angle into the tested material with following parameters: objective lens X50, load 10 N, indentation time 10 s. The average HV micro hardness value was determined from 10 measu- ring points (distances) on 70 samples of the hydraulic hammer case and from 10 measuring points (distances) on 200 samples of the hydraulic hammer clamping head. To measure dimensional and shape accuracy, Perthometer MAHR, equipped with PCV 350 slider unit with sensors with 350 mm length range and a mobile 6-axis 3D mea- suring arm Romer Absolute Arm 7535 with a working range of 3.5 m were used. This way, basic contour elements were determined: radii, distances and angles. Using the mobile 3D measuring arm, the tolerances of circularity, coaxiallity and perpendicularity were also measured. Technical drawings, contourrograph measuring protocols and tables of dimensional and shape precision deviations are listed in the conclusion of the article. Keywords: Hardness tests, dimensional and shape precision analysis, construction stainless steel, production engineering, construction and agricultural machines Introduction At present, all companies have been established and should maintain an Integrated Management System (IMS). This way, the management and thus the produc- tion and service are committed to meet the requirements of the Quality Management System (STN EN ISO 9001) and the Environmental Management System (STN EN ISO 14001). The permanent goal is to increase the effi- ciency by optimization of the entire production process. Product quality is a dominant factor that affects the development and success of production. To ensure a high level of product quality check, it is necessary to build an air-conditioned check center as well as quality check zones directly within the production itself, equipped with state-of-the-art measuring devices. Materials and methodes Construction and agricultural machinery consist of components that have to meet the tolerances of dimen- sional and shape accuracy as well as the hardness of the materials themselves. Based on the above, there were been performed hardness measurements on components of heavy machinery, namely on the clamping head and case of Montabert hydraulic hammer, currently a fairly young mark on the market. Manufacturers especially pay attention to high performance, taking into account the re- quirements for noise emissions and reduction of vibration transmitted to the operator [2, 5, 6]. The clamping head of the hydraulic hammer is made of Stainless Steel Class 41 4220 (1.7131, 16MnCr5) the case is made of Stainless Steel Class 41 5130 (1.7218, 25CrMo4) stainless steel case [1, 3, 7]. To verify the required quality of the products, follow- ing measuring devices were used: hardness was measured using the LM 700 AT Vickers Micro Hardness Tester, di- mensional and shape accuracy was determined using con- tourrograph Perthometer MAHR (Fig. 3) and mobile 6- axis 3D measuring arm Romer Absolute Arm 7535 (Fig. 4) and the roughness was measured by Mitutoyo SJ-301 roughness meter. Chemical composition of respective steels according to norm EN 10084-94 is stated in Tab. 1. Tab. 1 Chemical composition in wt. % of used construction stainless steels according to STN EN 10083 C Simax. Mn Pmax. Smax. Cr Mo Ni Cu Al Steel 41 4220 0.13 0.23 1.25 0.010 0.020 1.02 - 0.05 0.22 0.02 Steel 41 5130 0.20÷0.31 0.43 0.56÷0.94 0.030 0.040 0.85÷1.25 0.12÷0.33 - - - Hardness measurements were performed on the LM 700 AT Vickers Micro Hardness Tester (Fig. 2) using an X50 lens with a 10 N load for time 10 seconds. The Vick- ers hardness test is carried out according to the national