An anchor plate, floor plate or wall washer is a large plate or washer connected to a tie rod or bolt.[1]​ Anchor plates are used on the exterior walls of masonry buildings, as structural reinforcement. Being visible, many anchor plates are made in a decorative style.[2][3]​.

A popular style is the star anchor, an anchor plate cast or wrought in the shape of a five-point star. Other names and styles of anchor plate include earthquake washer, triangle washer, S-iron and T-head.[2]​ In the UK, pattern plate is the term for circular restraints, tie bar is an alternative term for rectangular restraints.[4]​[3]​.

Anchor plates are made of cast iron, sometimes wrought iron or steel, and are often used in brick or other masonry buildings. They are commonly found in many older cities, towns, and villages in Europe and in more recent cities with important brick building legacies of the 19th and 18th centuries, such as New York, Philadelphia, St. Louis, Cincinnati, and Charleston, South Carolina. The set of braces and plate reinforces the masonry wall against lateral bowing.[3]​.

According to the Oxford Dictionary of Construction, Surveying and Civil Engineering, an anchor plate "is a plate attached to a component that allows other components to be connected."[1]​.

Although there are many types of anchors or anchors, according to the Dictionary of Architecture and Construction, an anchor plate in particular is a "wrought iron clamp, of Flemish origin, on the exterior side of a brick building wall that connects to the front wall with a steel brace to prevent the two walls from separating; these clamps were often in the form of numbers indicating the year of construction, or letters representing the owner's initials, or were simply designs fantastic".[5]​.

While most types of anchors are made of steel only, anchor plates may also contain cast or malleable iron. The exterior wallwasher is usually made of a cast iron star or a flat steel plate.[6]​.