| 摘要 |
A method of making a metal frame is a consistent operation including material-choosing, cutting, jointing, riveting and shaping, wherein the material-choosing is to take coiled banding metal plates as material and the metal plates are cut into two I-shaped and two flat U-shaped metal components. One piece or more than one pair of protrusions and indentions is correspondingly set on the ends of each metal component and each arm of the flat U-shaped metal components. Upon jointing, engage the protrusions and indentations on the I-shaped metal components with the corresponding protrusions and indentations on the edges of two arms. Upon riveting, the inner edge of each protrusion and the outer edge of each indentation are respectively punched to make stamping marks. Upon shaping, punch and fold rims of the metal frame to become roughly vertical for making a metal frame with inverted L-shaped cross-section on each side.
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