本规范涵盖了适用于按英寸/磅尺寸订购的铝合金和镁合金挤压棒材、棒材、线材、形状和管材的既定制造公差。对于某些形状，可能需要大于标准的公差；其他产品的公差可能接近标准。然而，除非买方和卖方另有约定，否则此处显示的公差适用，并且适用于所有温度，除非另有说明。

This specification covers established manufacturing tolerances applicable to aluminum alloy and magnesium alloy extruded bar, rod, wire, shapes, and tubing ordered to inch/pound dimensions. Tolerances greater than standard may be necessary for some shapes; tolerances closer than standard may be possible for others. Tolerances shown here, however, apply unless otherwise agreed upon by purchaser and vendor and apply to all tempers, unless otherwise noted.