As shown, the male coupling end includes an enlarged collar formation 14 over a short distance, for example several inches, spaced from {HEAD ~ the tip} of {TAIL ~ 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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As shown , the male coupling end includes an enlarged collar formation 14 over a short distance , for example several inches , spaced from { HEAD ~ the tip } of { TAIL ~ 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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