including what we presently believe is the best mode of carrying out the invention referring to fig1 of the drawings reference numeral 1 indicates a saber saw blade with a flat sided body 2 and teeth 3 along a narrow edge of the body merely by way of illustration the body of the blade 1 is shown as having formed in it a number of different types of dimples although normally only one type of dimple would be used on any one blade spread along the length of the blade fig2 is an illustrative example of some of the dimples in the blade of fig1 wherein concave dimples 4 with ridges 5 along their perimeters are shown as being positioned directly opposite one another on two flat sides of the blade in fig3 the dimples are shown as being staggered with respect to one another on opposite sides of the blade fig4 which is a fragmentary sectional view taken along the line 4 4 illustrates concave dimples 7 without ridges with complementary convex dimples 8 with an outermost smooth domed surface 9 alternately on one side and the other fig5 illustrates a concave dimple 4 with a ridge 5 on one side and a complementary convex dimple 8 with an outermost smooth surface 9 fig6 is a fragmentary sectional view taken along the line 6 6 of fig1 showing.