Dimension

Type

in

mm

9 7/8

250.8

SK512G, SK542G, SK612G, SK732G

IADC

Recommended Parameter

Formation

Bit Pressure (k N/ mm)

Rotational Speed

(r / min)

512

0.35~0.7

120~60

mud stone, plaster stone , salt rock , soft shale , cotton rock

542

0.4~0.8

100~60

Medium soft shale , medium cotton rock , medium-soft sandstone

612

0.5~0.9

100~60

argillite, limestone, sandstone, dolomite

732

0.6~1.1

90~50

argillite, firm limestone, sandstone , siltstone, basalt , silexite, granite, quartzose sandstone, firm dolomite , firm limestone , pyrite