As shown, the male coupling end includes {HEAD ~ an enlarged collar formation} 14 over {TAIL ~ a short distance}, for example several inches, spaced from the tip of the male coupling end and a threaded, somewhat conical, nose portion 15 protruding therefrom, sometimes referred to as the pin, adapted to be mated with a female coupling end 13 of the next adjacent drill pipe section 
over
As shown , the male coupling end includes { HEAD ~ an enlarged collar formation } 14 over { TAIL ~ a short distance } , for example several inches , spaced from the tip of the male coupling end and a threaded , somewhat conical , nose portion 15 protruding therefrom , sometimes referred to as the pin , adapted to be mated with a female coupling end 13 of the next adjacent drill pipe section
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