Masking method for electrical bond preparation and strength property preservation about a hole

A chemically processed metal part, comprising:

• a first face;
• a second face opposite the first face;
• and
• a hole extending through the chemically processed metal part from the first face to the second face;
• and
• wherein an inner side surface defining the hole, a first area surrounding the hole on the first face, and a second area surrounding the hole on the second face are not chemically processed.

A metal part stack-up, comprising:

• a first chemically processed metal part having a first face, a second face opposite the first face, and a first hole extending through the first chemically processed metal part from the first face to the second face;
• a second chemically processed metal part having a third face, a fourth face opposite the third face, and a second hole extending through the second chemically processed metal part from the third face to the fourth face, wherein the first chemically processed metal part overlays the second chemically processed metal part such that the second face engages the third face and the first hole aligns with the second hole;
• and
• a fastener received through the first hole and the second hole;
• wherein a first inner side surface defining the first hole and a second inner side surface defining the second hole are not chemically processed;
• wherein a first area surrounding the first hole on the first face, a second area surrounding the first hole on the second face, a third area surrounding the second hole on the third face, a fourth area surrounding the second hole on the fourth face are not chemically processed;
• wherein a faying surface electrical bond is formed between the first chemically processed metal part and the second chemically processed metal part through the second area and the third area;
• wherein a spot electrical bond is formed between the first chemically processed metal part and the second chemically processed metal part through the first area, the fastener, and the fourth area;
• and
• wherein a fastener shank electrical bond is formed between the first chemically processed metal part and the second chemically processed metal part through the first inner side surface defining the first hole, the fastener, and the second inner side surface defining the second hole.