可以使用轧制钢、铸钢或坩埚钢、或者铸铁装置，不允许用生铁。

Rolled, forged, or cast steel, or malleable iron fittings may be used. Cast iron is not permissible for fittings.

youdao

可以使用轧制钢、铸钢或坩埚钢、或者铸铁装置，不允许用生铁。

Rolled, forged, or cast steel, or malleable iron fittings may be used. Cast iron is not permissible for fittings.

youdao