Sanwa Kokan Co., Ltd

Sanwa Kokan Kabushiki Kaishas

Yutaka Sunaga

Toshio Sakurai

A method of and a device for cold drawing seamless metal tubes, each tube having an upset portion on both ends. The draw bench comprises a reducing die, a die control unit, a plug control unit including a plug and a draw unit. The reducing die has an internal surface including an inlet portion which tapers rearwardly, a small diameter bearing portion and an oppositely inclined outlet portion. A plug includes a rearwardly tapered portion, a large diameter bearing portion, a forwardly tapered portion, a small diameter cylindrical portion, a rearwardly tapered portion and a large diameter cylindrical forward bearing portion. The plug control unit is mainly movable with respect to the die control unit by a pair of hydraulic units, but the control unit is also movable with respect to the plug control unit for changing a cross sectional reducing area between the reducing die and the plug.

Methods for cold drawing seamless metal tubes each having an upset

A method of cold drawing seamless metal tubes each having an upset portion on each end. A draw bench used for carrying out the method of this invention comprises a die control device, a plug control device including a plug having large and small diameter bearing portions and a draw unit. The die control device and the plug control device are movable with each other for changing a cross sectional reducing area between the reducing die and the plug. The method is characterized in that the cross sectional reducing area between the reducing die and the plug is preferably changed in accordance with the desired forms of a mother tube to be drawn by longitudinally transferring the reducing die and the plug and fixing them at the selected positions.

Method of cold drawing seamless metal tubes each having an upset portion

A draw bench for cold drawing seamless middle tubes having upset portions on both ends. The draw bench includes a die control device, a plug control device including a plug having large and small diameter bearing portions and a draw unit. The die control device and the plug control device and the plug control device are moveable with respect to each other for changing the cross-sectional reducing area between the reducing die and the plug.

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Kawasaki, Japan

Yutaka Sunaga