Open the blades
Before you open the blades of the lopping shears, do not forget to wear appropriate gear which includes goggles and eye protectors to save yourself from metal shavings. You should now open the blades of the shears, securing one blade tightly in a bench vice.
Examine the blade
In order to determine the angle of the edge, you should examine the blade closely. The edge of the blade is called a bevel and it represents the cutting surface. To maintain tool integrity, it is important that you follow the bevel and do not work against it to create a sharper or wider edge.
Grab a wire brush and clean the blades thoroughly to ensure that there is no dirt on them. On the clump of the steel wool, you would have to apply additional pressure to tackle the rusty areas. Keep in mind that a smooth blade surface is crucial for effective sharpening. As you proceed through the sharpening chore, the handle of the wire brush can be used to clean shavings from the mill file.
Hold the mill file firmly
By placing both hands at the end of the mill file, you need to grasp it firmly. Two hands allow even pressure and additional control on the cutting surface, as mill files cut on the push strokes. The mill file needs to be placed at an angle which matches the bevel of the blade, and now you can push forward through a firm stroke. On the return stroke, you should lift the file off the surface of the blade.
Blow away metal shavings
In order to determine your progress in sharpening the lopping shears, you should brush or blow away the metal shavings after every couple of strokes. You can now insert the next blade by unclasping the tool from the vice, and repeat the same procedure on the other blade.