Abstract: A pair of cams having helical ramps rotate on each other to produce an extension or retraction of the cams. A handle on one of the cams provides leverage for turning the cam to convert radial force to axial force. The cams can be used in conjunction with a shaft and ratchets to produce jacks. The cams can also be used to produce clamps such as for securing lids to containers. When a shaft is secured at one cam and connected to a trailer, truck or other vehicle bed, an object can be secured to the vehicle bed by the other cam engaging and placing a downward force on the object when in the extended position. When used as a clamp the cams can secured or release the object being held with a partial rotation of the cam. The cams are simple one piece devices having a bearing portion on one cam inserted into a bore on the other cam to provide concentric rotation of the cams. There are no moving parts to wear out or break. The cams and handle can be scaled up or down to any size needed.