A tangless buckle system for straps for watches, fitness monitors, and other limb-worn devices. In such tangless buckle systems, a buckle with a tooth is provided. In contrast to a traditional buckle, the tooth and the buckle are fixed with respect to one another, i.e., the tooth does not rotate relative to the buckle. As this new buckle design does not include the rotating tang that extends all the way across the buckle loop in a traditional buckle design, the new design may be referred to as a “tangless” buckle. Such buckles may provide a simpler, yet highly secure, mechanism for securing such devices.