Novel crab -bolt

The utility model relates to a novel crab -bolt, including the crab -bolt main part, the crab -bolt main part including the polished rod portion that lies in the middle part with lie in the tip and possess screwed screw portion, its characterized in that, the middle part outside of polished rod portion except that both ends is equipped with the shrink sleeve pipe, the shrink parcel takes place in polished rod portion for the back that is heated for the shrink sleeve pipe, the both ends outside of polished rod portion is equipped with the plastic sheath, plastic sheath outer wall and polished rod portion no. 1 that tightly sleeve pipe one end is being shunk in the adhesion serve, shrink sleeve pipe and plastic sheath are the flexiplast pipe. The utility model discloses the shrink sleeve pipe can avoid the crab -bolt direct with the concrete contact, in the plastic sheath can prevent that steam from getting into polished rod portion from shrink sleeve pipe both ends, can guarantee the corrosion resistance of cr