PURPOSE: To economically manufacture a staple easy to drive, hard to draw and not to be overdriven by bending U-shaped staple leg parts forcedly and turning the points of the legs toward the obliquely external sides.

CONSTITUTION: The U-shaped staple S transferred keeping vertically for a fixed distance turns its head downward with the fall of a conveyor 2, enters a coating liquid tank and the upper part of the head is dipped into the coating liquid and adhered to the liquid. The sectional shape of a separation click 5 at a place where the staples S1 which are solidified after they pass through the inner part of a neighboring furnace and advance beyond the separation clock 5 located at a slightly cooled place slip out a little from a guide groove 16 is formed by a die part 11. When the staple S comes to the prescribed position, the high part of a cam 14 is opened forcedly by a roller 9, a pushing tool 7 is pushed and clasped to a groove form part 23 formed by a support pin 10 on both sides of a bending metallic part 11 and formed. The distance between both legs at a forcedly bent place is narrowed, even when coated wire is held by both ends in the shape of a letter 8, both staple legs S1 look obliquely outside, as the staples are driven in, the obliqueness becomes stronger and larger resistance occurs to draw the staple.