The concrete tamper forces the suspended, coarse aggregate--meaning chunky rocks--below the surface of freshly poured concrete. Tamping results in a smooth surface for finish work and a stronger, consolidated unit of concrete. Tampers have a broad, flat surface--usually a grid of welded steel from which handles protrude to about chest level. The concrete worker lifts the tamper by its handles and pounds it onto the wet concrete, pushing rocks below and allowing cement to remain on the surface.
A straightedge, also called screed, as applied to masonry work, is a metal bar used to level the exposed surface of a fresh pour during a process referred to as "striking off." Bars used to strike off concrete are fashioned straight and truly square to produce an even plane. The straightedge is placed across adjacent forms and drawn or shimmied across the newly poured surface to remove excess concrete.
The float smooths a sidewalk's surface after it has been leveled by a screed. Floats are smooth, solid pieces of metal attached to hooked handles or poles. Masonry workers gently push the float across the concrete's surface to fill in gaps, eliminate voids and remove marks.
The distinguishing feature of the edger, a type of trowel, is a metal plate bent into an angle. A handle protrudes from the obtusely-angled side of the tool, allowing masonry workers to run the tool along outside corners, such as the corner of a curb. Edging tools shaped at the precise angles and lengths required for sidewalk curbs are called curb edgers.
The cove tool, also called an inside edger, is an edger with the handle protruding from its acutely-angled side, allowing a masonry worker to run the tool along inside corners, such as gutters. The counterpart of the curb edger is called the gutter tool, a tool formed to the angle and lengths required for shaping gutters.
The metal plate of a curb and gutter trowel combines the inside angle of a cove tool and the outside angle of an edger into one tool; the tool's plate bends twice to create a rough "S" shape. Curb and gutter tools appear with varying angles, lengths and radii according to application.