Pipe threading lathe (also called oil-country lathe) is a horizontal lathe specially designed for turning large-diameter pipe fittings. It is characterized by a relatively large through-hole diameter of the spindle (generally more than 135mm) and chucks to facilitate the clamping and processing of large-diameter pipes or rods. This special lathes are widely used in mechanical processing operations, like internal and external pipe threading, process and repair drilling pipes/collars, kelly, joint and sleeve in machinery manufacturing, petroleum, chemical, coal, geological exploration, urban water supply and other industries. 

Pipe threading lathes have a large through hole in the spindle box. After the workpiece passes through the spindle hole, it is clamped by two chucks located at both ends of the spindle for rotary motion. Usually, spindle bore diameter for this type of lathes  is 135mm ~ 500mm, the maximum swing diameter over bed is 630mm ~ 1200mm and the maximum workpiece length is from 750mm to 15000mm.