All our positioners have slots that allow the workpiece to be bolted to the face. Welding the part to the positioner is often a good way to prevent shear forces from sliding the part as it is maneuvered. Any of these methods, whether stand-alone or combined, will work if applied properly.
Even with small positioning equipment it is important that the unit be mounted to a flat, even surface to prevent it from tipping. If mounting holes are provided, they should be used to secure the positioner to a stable surface to prevent tipping when or if it encounters an unexpected force. The positioner mounted to a workbench or stand must be secured as well.