A backing pad is a power tool attachment that secures and supports accessories used for sanding and polishing. The abrasive or polishing medium is held securely on the face of the backing pad by means of a locking disc or hook and loop fasteners. Some types of pad feature an integral drive mandrel or shaft while others attach to the spindle of the tool via a locking disc. Backing pads are manufactured from a variety of materials including rubber, aluminum, and composite resins. They are available in a wide range of sizes and specialist designs for specific applications.
Backing pads serve as supports for soft or flexible polishing mops and abrasive discs used in power tools. They offer a secure yet pliable mounting that allows the sanding disc or pad to maintain good surface contact with both flat and contoured surfaces. The pad also ensures that the maximum surface area of the attachment is made available while polishing or sanding. When sanding, the backing disc keeps the disc flat at all times preventing the edge of the disc from scouring the work piece.
A backing pad is attached to or inserted into a power tool in two basic ways. The first is a shaft or mandrel built into the pad body. This variant is used in power tools equipped with jawed chucks such as hand drills. It is usually made of rubber and has a sheet of Velcro or hook and loop material permanently attached to its working face. Discs and mops designed for use with these kinds of pads have a corresponding hook and loop sheet attached to them which allows for secure attachment to the backing pad.
Pads designed for use in tools such as angle grinders have a central flange or shoulder build into them which fits over the spindle of the grinder. The discs have a similar hole in their center and are fitted over the tool spindle against the backing pad. The power tool locking nut is then tensioned, thereby locking both the pad and disc firmly in place. These backing pads are usually made of aluminum and are generally used for heavy duty sanding.
Backing pads are available in a range of sizes corresponding to standard available disc and mop sizes. Apart from rubber and aluminum, composite resins and high impact plastics are also commonly used to make backing pads. Special features such as profiled faces and cooling vents or fins are often integrated in the pad design for high demand applications. These additions aid in extending the life of the abrasive and protect the workpiece from overheated discs.