Abstract: A chain tool has a base body being cylinder like and having a groove formed in an end of the base body, and two wall portions being formed and faced each other on two sides of the groove. The two wall portions have two side surfaces. An inner thread portion is formed on the side surfaces along a direction of groove depth, the base body is laterally penetrated by the groove along a center of inner thread portion, a bottom portion connects the two wall portions and having a through hole formed therein and being coaxial to the inner thread portion; a drive bolt having a top rod and a screw rod being movably engaged with the inner thread portion, wherein the screw rod has a drive portion placed against to the top rod, the top rod is coaxially align to the through hole.

Abstract: A chain tool has two members each having a first edge formed with an opening to be engaged with the opening of the other member so that the two members can be pivoted with respect to each other. Each member has an opposite second edge provided with a recess and also has a guide groove in communication with the recess and the corresponding opening, wherein the recess is lightly deeper than the guide groove. Each member further has a rib extending along the corresponding first edge and projecting into the corresponding opening to form a protruding portion. When the openings of the two members are brought into engagement, the protruding portion of each member is moved along the guide groove of the other member into engagement in the recess of the other member.