These pipes are manufactured with one end of the pipe as male threaded whereas; other end is female threaded socket. Threads are either V or trapezoid type and protection caps are provided on the threads to protect the threads in transit. Three types of pipes i.e., Shallow Well (C.S.) Medium Well (C.M.) and Deep Well (C.D.) are available. Shallow Well pipes can be used for depths up to 80 metres, Medium Well pipes can be used up to 250 metres. Deep well pipe can be used upto 450 metres.