An algorithm for determining the lower confidence limit (NDH) for the minimum value of the hardness of a set of machine parts by calculation is developed. For processing of statistical data of the hardness measurements used a three-parameter Weibull distribution is offered. The transition from sample data to population data is carried out by the graphical method. According to the algorithm, NDH was found for the minimum hardness value with confidence probabilities p=0.9; 0.92;0.93;0.94.

Keywords: hardness, machine parts, sampling, aggregate, lower confidence limit, graphic method, calculation method

The study on the hardness of samples from steel ST3 and 15G. On the basis of the correlation equations obtained values of ultimate strength of the examined steels. With the application of the law of three-parameter Weibull distribution constructed density distribution and the resulting minimum value of ultimate strength. The obtained results are proposed to use to determine the value of the resource for load-bearing systems of vehicles.

Keywords: reliability, lifetime, the hardness of steel, strength of steels, the endurance limit of steels, the Weibull law

The analysis of existing methods of water use when applied galvanic coatings in the automobile transport sector. It is established that under the existing schemes of water use in the galvanic production wastewater after cleaning goes into the sewer, keeping the risk of contamination of open reservoirs. In such circumstances, the most effective is the use of system of the closed water cycle, which with the help of automatic control allows to take into account changes in the concentration of substances laundered in the washing baths providing the required quality of washing parts with a minimum consumption of water resources.

Keywords: water purification, electroplating system, the water cycle in the galvanic system

The task of identification of defects in rods with different variants of fastening. In the basis of lies method parameter identification based on an analysis of the frequencies and parameters of natural modes of the structure. Built model of the rod design has defects fluctuations, using finite element of the complex 

Keywords: Defect, damage, rod, the oscillations of the cantilever rod