滾球式平底磨鞋是用底面所堆焊的YD合金去全面磨碎那些卡死在井內無法打撈的鋼鐵落物，并且在磨鞋圓柱面上有可以起扶正作用的滾球，使磨鞋在井眼內工作時不磨銑套管內壁。
The rolling--ball flat--bottom mill shoe whose bottom face is overlaid with YD alloy is used to fully grind junks which is stuck downhole and  impossible to be caught. Additionally, rolling balls which are dressed on cylinder face of mill shoe can guarantee the mill shoe not to mill casing inside wall during milling operation in hole.

技術規(guī)格及參數(shù)

型號	外形尺寸	接頭螺紋	下入套管
GQM140	ф118×460	NC31	5 1/2"
GQM168	ф146×480	NC38	6 5/8"
GQM178	ф155×500	NC38	7"