A slender blade coated with diamond dust or a similar material and used to cut extremely hard materials.
Rodding
A method of using a straight edge to align mortar with the float strips or screeds. This technique also is called floating, dragging or pulling.
Roll roofing
Roofing material of fiber and asphalt manufactured in rolls.
Roll welding
Form of welding using a heat source and rollers to join two surfaces.
Rollback
The reduction of prices to a previous level by government control or a limitation on annual value increases, usually associated with property tax.
Roller
A paint application tool having a revolving cylinder covered with lambswool, fabric, foamed plastic, or other material.
Roller bearings
Roller bearings work in the same fashion as ball bearings, but the bearings themselves are either cylindrical or conical rollers. Cylindrical rollers will carry only radial loads, while conical rollers carry both radial and thrust loads.
Roller catch
A type of cabinet door latch. A projection on the door is inserted between to rollers when closed, thus securing the door shut.
Roller hanger
A pipe hanger similar to a clevis hanger except that the yoke bolts to a roller rod instead of a metal strap. This roller rod supports the pipe and permits horizontal movement.
