Slide fastener is a closure device consisting of interlockable elements each attached to one of the opposing edges of two tapes and a movable part called a "slider" that spans the interlockable elements. The different types of slide fasteners are defined by the material of the elements (teeth), which form their fastener chains. They can be of metallic, molded plastic or monofilament plastic construction. In this study, it is aimed to investigate the effect of chain width on the strength of the slide fastener. For this purpose, 5 metallic slide fasteners with different chain widths and properties were supplied, then lateral (crosswise) strength, element pull-off and element slippage tests were performed and the results were analyzed statistically.