The design is the shape of the SHOVEL BLADE shown in the drawings.The portions of the designs that are shown in dotted lines are for illustrative purposes only and do not form part of the claimed design.Figure 1 is a front elevation view of a first variant of a shovel blade;Figure 2 is a rear elevation view of the first variant of the shovel blade of Figure 1;Figure 3 is a bottom elevation view of the first variant of the shovel blade of Figure 1;Figure 4 is a top elevation view of the first variant of the shovel blade of Figure 1;Figure 5 is a left side elevation view of the first variant of the shovel blade of Figure 1;Figure 6 is a right side elevation view of the first variant of the shovel blade of Figure 1;Figure 7 is a front elevation view of a second variant of a shovel blade;Figure 8 is a rear elevation view of the second variant of the shovel blade of Figure 7;Figure 9 is a bottom elevation view of the second variant of the shovel blade of Figure 7;Figure 10 is a top elevation view of the second variant of the shovel blade of Figure 7;Figure 11 is a left side elevation view of the second variant of the shovel blade of Figure 7;Figure 12 is a right side elevation view of the second variant of the shovel blade of Figure 7;Figure 13 is a front elevation view of a third variant of a shovel blade;Figure 14 is a rear elevation view of the third variant of the shovel blade of Figure 13;Figure 15 is a bottom elevation view of the third variant of the shovel blade of Figure 13;Figure 16 is a top elevation view of the third variant of the shovel blade of Figure 13;Figure 17 is a left side elevation view of the third variant of the shovel blade of Figure 13;Figure 18 is a right side elevation view of the third variant of the shovel blade of Figure 13;Figure 19 is a front elevation view of a fourth variant of a shovel blade;Figure 20 is a rear elevation view of the fourth variant of the shovel blade of Figure 19;Figure 21 is a bottom elevation view of the fourth variant of the shovel blade of Figure 19;Figure 22 is a top elevation view of the fourth variant of the shovel blade of Figure 19;Figure 23 is a left side elevation view of the fourth variant of the shovel blade of Figure 19; andFigure 24 is a right side elevation view of the fourth variant of the shovel blade of Figure 19.