Attachments for a clamping device can be used to increase the contact area between the jaws and the object to allow the clamping device to handle irregular objects, such as non-flat panels of metal, granite, ceramic, glass, quartz, or concrete plates. The attachments can include plate assemblies to be attached to the sides of the irregular objects. The attachments can include jaw plate assemblies to be attached to the sides of the jaws of the clamping device.