An edge protector for an electrolysis electrode, has an outer surface shape in the central portion thereof which reduces the thickness in that portion to improve uniformity of cooling, and thereby reduce stress cracking as a result of the reduced buildup of thermal stresses. The outer surfaces may be inclined planes or suitable curved shapes that converge from an outer jaw toward an inner jaw. In one embodiment an edge protector includes a sealing member made of a sealing material such as silicone rubber, either integrally formed with the inner jaws, or affixed after forming. A spreader bar has a shape which enables clamping of the edge protector onto a mother blank without excessive expansion of the outer jaw, thereby lengthening service life, and easing installation. A tapered spreader bar for end insertion, and embodiments of spreader bars having flattened surfaces for edgewise insertion and then rotation for tightening are disclosed.