Q 3 ? 12 ¾ / 75 (B type)manual tong is an essential tool in oil drilling operation to fasten or remove the screws of drill pipe and casing joint or coupling. Applicable column range: 3 ? in ~ 12 ¾ in. maximum torque is 75kN • m. Column and torque of different diameters can be adjusted by changing the latch lug jaws or latch steps.