| 摘要 |
PROBLEM TO BE SOLVED: To provide an extrusion method to obtain an extruded product of high strength without generating defective welding in extruding a metallic product having a hollow cross section made of aluminum etc., by a bridge die. SOLUTION: In extruding a metallic product having a hollow cross section by a bridge die 3, defective welding of an extruded product is prevented by keeping the temperature of a beam part 12 of a bridge of the bridge die 3 by a heater 30 etc., after the bridge die is fitted in an extrusion press or waiting for the fitting in the extrusion press, and before the extrusion is started.
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