... 0.70-1.20RPM(r/min)70-40Bearing TypeRubber Seal Sliding BearingTypeDrill BitAPI Regular Pin(inch)4 1/2 ... and decreasing the breakage rate by using the tungsten carbide compact of high strength and toughness.b. ... 637G9 1/2241.3437G, 517G, 537G, 547G, 617G9 5/8244.5437G, 517G, 537G, 547G, 617G9 7/8250.8437G ... 537G, 617G, 627G, 637G 7 7/8" Kingdream HA737G tungsten carbide tricone drill bit /three cone bit