Home > Products > Industrial Supplies > Machine Hardware > Other Machine Hardware

  IADC WOB(kN/mm)(bit dia) RPM(r/min) Applicable Formations 437  447  0.35--0.9 240--70 Very soft with low compressive strength and high drillability,such as shale,clav,chalk,mudstone,gypsum,sandstone,soft limestone 517  527  0.35--1.0 220--60 Soft with of low compressive and high drillability,such as 
mudstone .gypsum,salt ,soft shale ,soft  limestone.etc. 537  547  0.45--1.0 220--50 soft to medium with low compressive strength ,such as
medium soft shale,medium soft limestone,medium soft
sandstone and medium formation with harder and 
abrasiver interbeds .etc. 617  627 0.45--1.1 200--50 Medium hard with high compressive strength such as limestone hard shale ,sandstone and dolomite,etc. 637 0.5--1.1 180--40 Hard fomation with high compressive strength ,such as
limestone,dolomite,sandstone,hard gypsum,and marble
.etc.