DICE FOR COLD DRAWING OF PIPE - NIPPON STEEL & SUMITOMO METAL CORP

Title:

DICE FOR COLD DRAWING OF PIPE

Document Type and Number:

Japanese Patent JP2014018814

Kind Code:

A

Abstract:

To provide a dice for cold drawing of a pipe, which enables the drawing to be performed without causing cracks.

In a dice 1 for cold drawing, a bearing diameter and a tip diameter of the dice satisfy the following expression (1), and an external radius working ratio Δr/L of immediately before the bearing satisfies the following expression (2), where Δr is an external radius working amount defined by (internal diameter of the dice in 5 mm position immediately before the bearing - a bearing diameter)/2 (mm), and L is a distance between the bearing and an external radius working amount set portion (for example, 5 mm). The expressions are: 0.80<bearing diameter/tip diameter<0.93...(1); and 0.03≤Δr/L≤0.26...(2). Particularly, the dice exhibits an effect for drawing of hard-to-work materials such as two-phase stainless steel or high alloy.

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