GB/T 4909.4-2009 in English

GB/T 4909的本部分规定了裸电线扭转试验的试验设备、试件制备、测量步骤、试验结果及评定等。
本部分适用于测定标称直径de为0.300mm～10.00mm的铜、铝及其合金、双金属线等圆截面导体及特征尺寸d≤20.00mm的异形截面导体（如接触线等）的扭转性能。
本部分是将规定长度的试件，以其自身的轴线为中线扭转，直至断裂或达到规定的扭转次数为止。
本部分应与GB/T 4909.1-2009一起使用。

Scope

This part of GB/T 4909 specifies the test equipment, sample preparation, measurement procedures, test results and evaluation of the bare wire torsion test. This part is applicable to the determination of the torsional performance of circular cross-section conductors such as copper, aluminum and its alloys, bimetallic wires with a nominal diameter d of 0.300mm~10.00mm, and special-shaped cross-section conductors with a characteristic size a≤20.00mm (such as contact wires, etc.) . This part is to twist the test piece of the specified length with its own axis as the center line until it breaks or reaches the specified number of twists. This section should be used together with GB/T 4909.1-2009.