Kelly Bars

Frictional pressurizing Kelly bar The external key of the frictional pressurizing Kelly bar has three or six keys (straight bar), there is no large concave pressuring table in the middle (look at fig), and there are three keys or six keys wear-resistant bar in the internal key. When the diving sets push the straight bar of the external key of the Kelly bar , to drive the rotary drill, The peripheral force which is produced when the Kelly bar rotaries pass down pressure to produce friction to produce pressure , This Kelly bar pressure transmission in general applicable to the Kelly bar soft construction of the layer formation or drift sand formation ,Grinding resistance pressurizing kelly bar is usually formed by five sections or six sections, with the depth in the range of 50-90 meter. TypeOuter pipe diameter (mm)SectionDepth (M)Torgue (KN.M)ZH340377540-56150ZH406406560200ZH406406560-62220ZH440440570250ZH450450570250ZH508508690250