Physical Wear and Tear of the Means of Labour, the wear and tear as a result of which the means of labour (see Means of Production) lose their technological and production qualities and use value. "The material wear and tear of a machine is of two kinds. The one arises from use, as coins wear away by circulating, the other from non-use, as a sword rusts when left in its scabbard" (K. Marx, Capital, Vol. I, p. 381). The wear and tear of the first kind is to a greater or lesser extent proportional to the use of the machine, while the wear and tear of the second kind is inversely proportional, to a certain extent, to its use. Under socially normal conditions of the use of the means of labour, their value is returned at the cost of its being transferred, by parts, to the product being created. The cost of the means of labour, transferred to the product proportionally to their wear and tear, assumes the form of depreciation deductions (see Depreciation), which are used for the full or partial restoration of the means of labour. If the means of labour are used in conditions below the socially normal (idling, breakdowns, low intensity of use, etc.) wear and tear is not restored, and entails losses. The physical wear and tear of the means of labour from non-use also ends in irretrievable losses and reduction of the national wealth. Good care of the means of labour, their speedy introduction into production and the observance of maintenance standards considerably reduce physical wear and tear. All these factors prevent the means of labour from premature breakdowns and idling. Alongside the physical wear and tear there is also the obsolescence of the means of labour.