the inner diameter of box 14 is greater at metal sealing surface 34 than at bore surface 39 sealing surface 34 on box 10 is protected from damaging contact during stabbing as indicated by the misaligned stabbing occurring in fig4 6 a portion of pin threads 16 may contact the tapered guide surface 35 but will not contact sealing surface 34 as shown in fig5 the larger inner diameter of guide surface 35 as well as step 37 and smaller diameter bore portion 39 prevent contact similarly pin nose sealing surface 28 is protected from damaging contact during stabbing even if misaligned as shown in fig6 box threads 22 may contact guide surface 29 but not sealing surface 28 because of its smaller outer diameter two stress relief grooves are formed on box 14 the lower box stress relief groove 40 is located adjacent to the inwardly facing internal sealing surface 30 the upper box stress relief groove 42 is located at the base of the threads 22 spaced axially a short distance from groove 40 these box stress relief grooves reduce the incidence of stress fractures of the box 14 thereby improving the fatigue life of the connection 10 two stress relief grooves are formed on box 14 the lower box stress relief groove 40 is located adjacent to the inwardly facing internal sealing surface 30 the upper box stress relief groove 42 is located at the base of the threads.