The outer portions of the float shoe are made of steel and generally match the casing size and threads, although not necessarily the casinggrade.
浮鞋的外壁由钢制成，且一般与套管的尺寸和丝扣匹配，然而浮鞋的钢级不一定要与套管钢级一致。
2
The outer portions of the guide shoe are made from steel, generally matching the casing in size and threads, if not steel grade.
引鞋的外部由钢制成，一般与套管的尺寸和螺纹匹配，如果钢级不匹配的话。
3
Through researching N80Q steel kind and the heat treatment technology, we have successfully developed and produced N80Q grade oil casing which meets the API standard and the user's requirement.