One approach to lock strap ends is to cut, or "notch" the seal and the strapping it joins to develop tabs at the edges. These tabs are bent down (down notch joint) or bent up (reverse notch joint). The strength of the notch joint comes from the mechanical interlock between the seal strapping. Notch joints are typically used in waxed strapping in packaging and unitizing applications.
Another way to seal the ends of strapping is to press or "crimp" undulations into the seal and strapping ends. The strength of the crimp joint issues from the deformed seal creating high frictional forces. Crimp joints create high static and dynamic joint strengths are used in applications like carloading in which the strapped load is subject to severe impact.
Seallesss joints can be created with manual strapping tools or pneumatic combinations strapping tools. Using interlocking keys, the sealless joints provide static joint strength equal to that of notch-type joints. The reverse lock sealless joint emphasizes one reversed interlocking key for added security in impact conditions.