The female coupling end portion likewise has {HEAD ~ a female end collar formation} 16 surrounding {TAIL ~ a female threaded section} or socket portion 17 into which the threaded nose or pin portion 15 of the next adjacent drill pipe section adjoining the female end 13 is to be inserted to couple the pipe section together 
surrounding
The female coupling end portion likewise has { HEAD ~ a female end collar formation } 16 surrounding { TAIL ~ a female threaded section } or socket portion 17 into which the threaded nose or pin portion 15 of the next adjacent drill pipe section adjoining the female end 13 is to be inserted to couple the pipe section together
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