Clamp-style shaft collars act to compress the collar and lock it into place using friction. They are easy to use and do not damage the shaft. The compression of the screws on the collar imposes a uniform distribution of force on the shaft. The resulting holding power is nearly double that of set-screw collars. However, in single piece clamp-style designs, the non-tightened side provides negative force, as it must also hold the collar open to allow it to be placed onto the shaft. The single screw tightener works against this force as well as providing a clamping force of its own. In contrast, the two-piece clamp-style shaft collar can be disassembled or installed in position, without having to remove other components from the shaft. This two-piece design provides greater clamping force than a single piece clamp because all of the force is transferred directly into clamping the shaft. Two-screw clamps still provide force on two sides (one dimension) only. Four (or more) screw clamps provide force on four (or more) sides, and thus two dimensions.