Abstract: A device is presented for measuring residual stresses in a solid component. he device includes a hardness measuring component which has an indenter for determining hardness at various locations. Stress (.sigma.) data is obtained by converting the hardness measurements according to the formulaa.multidot.[.sqroot.4P.sub.o.sup.2 -3P.sup.2 -P],where a is a constant in Kbar.sup.-1 mm.sup.2 /kg, which depends on the type of material under test and also on the type of indentor used, where the pressure p is measured in kg/mm.sup.2, and where the average pressure p.sub.o is the average value of mean pressure p along a radial cut line of the solid component specimen.