Packing fastener and packing box coupled together therewith

A packing fastener, comprising:

• a base member including:
• a first tubular portion that is inserted in overlapping through holes formed in two or more pieces of a packing material;
• a flange portion that is provided on a first opening edge of the first tubular portion at one end thereof;
• a pair of hook members that are coupled via first hinge portions to opposite inner side faces of the first tubular portion, the pair of hook members being bendable, about the first hinge portions as hinge axes, outward of a second opening edge of the first tubular portion at another end thereof;
• and
• a key member that has a second tubular portion that is removably insertable in the first tubular portion of the base member via the first opening edge, the key member being coupled to the flange portion via a second hinge portion perpendicular to the first hinge portions,
• the first tubular portion being inserted in the through holes starting with the second opening edge and then the second tubular portion being inserted in the first tubular portion so that the hook members pivot about the first hinge portions as hinge axes toward the second opening edge of the first tubular portion to project out beyond the second opening edge so as to face the flange portion, resulting in the two or more pieces of the packing material being held between the flange portion and the hook member,
• wherein
• the pair of hook members are, with no external force applied thereto, arranged in a wedge shape as seen in a sectional view so as to be increasingly close to each other toward tip ends, and
• each of outer side faces of the first tubular portion has a slope that is inclined inward from the first opening edge toward the second opening edge.