Bit Size

6"(152.4MM)

IADC Code

127

Connection

3 1/2"API   reg pin

Rotary Speed(rpm)

180~80

Weight on Bit(KN/MM)

0.35~1.05

Formation

Medium formation with high compressive strength   ,such as medium soft shale,medium softlimestone,medium soft sandstone,medium   formation with harder and abrasive interbeds,etc.

116/117

Low compressive strength, high   drill-ability and extremely soft formation, like  soft shale,   clay,  conglomerate etc.

0.35~0.90

180~80

126/127

Low compressive strength, high   drill-ability and soft formation, like shale, clay, soft limestone, salt   rock, etc.

0.35~1.00

180~80

136/137

Soft to medium soft with low   compressive strength or soft with hard interlayer, like anhydrite, soft   limestone,sandstone, etc.

0.37~1.05

130~60

216/217

Medium hard formation with   relatively high compressive strength and hard interlayer, like hard shale,   sandstone, limestone, etc.

0.5~1.20

100~50