The mill shoe include flat-bottom mill shoe, concave-bottom mill shoe, tapered bottom mill shoe, pilot mill shoe£¬pear¨Cshaped mill shoe, washover shoe, high effective cone mill shoe. The flat-bottom mill shoe is a normal tool for grinding downhole small catches and repairing the fish top. The concave-bottom mill shoe is used to grind downhole small objects and other unstable fallen objects.The pilot mill shoe is used to grind the fallen objects which are with internal hole and shaking downhole. The tapered bottom mill shoe is used to repair and maintain small deformed location and clean wall sundries.

Technical parameters and specifications

Technical parameters and specifications for pilot mill shoe

O.D.(mm)	O.D. of the milled tube(mm)	Wing length (mm)	Thread connection	Suitable hole size (mm)
97	73-89	150	NC26	107.9~114.3
121	90-102		NC31, 2 7/8REG, 3 1/2REG,	130.0~139.7
130	100-160	200		142.9~152.4
140	110-120			155.6~165.1
156	127		3 1/2REG,	168.0~187.3
178	158-168		4 1/2REG,	190.5~209.5
200	168-178			212.7~241.3
232	194			244.5~269.9
257	210-219	250	6 5/8REG,	273.0~295.3
279	220-230			298.5~317.5
295	240-246	300		320.6~346.1
330	273			349.3~406.4
381	320			406.4~444.5

Technical parameters and specifications for washover shoe