man with drill
A ground joint is a machined or tight-fitting joint that makes a tight fit without packing. In masonry, it is a structurally cohesive joint formed by two blocks, usually without the use of mortar. A metal pipe ground joint is one that makes a tight seal without the use of washers or gaskets. A glass frosted joint is made by grinding glass with sand or emery to make a well-fitting lid for a bottle or jar. The term “ground” refers to the grinding of the material that forms the gasket.
A ground masonry joint can be stronger than a mortar joint. A famous example is the enigmatic stone walls of the Machu Picchu ruins in Peru, formed from rock melted so precisely that the joint is too narrow to accommodate even a sheet of paper. These types of joints, made with little or no mortar, are more common in fine stone than in masonry or rough. Industrial floor slab components are often fitted with grouted joints because tight, groutless joints are resistant to cracking or spalling due to the heavy loads these slabs must withstand.
Joints for joining steel, iron, or copper pipes that incorporate a malleable copper or brass ring at the joint, ground to form a tight seal when the joint is tightened, are called ground joints. The union is an accessory that allows the union of threaded pipes without the need to disassemble and reassemble them, being necessary when a component, such as a meter or regulator, must be installed in a gas, water or compressed air line. The precision ground ring makes the seal more reliable and tighter than a rubber or plastic washer. A ground bond is not the same as a ground bond, which is an electrically grounded connection that allows static electricity to discharge and is used for propane connections.
Ball or conical joints in glassware make a bottle or flask gas-tight, liquid-tight, or vacuum-tight. They typically consist of a grounding opening, a plug, a plastic sleeve, and a clamp. Glass is polished with a combination of emery and oil or fine sand and water, and the glove is usually made of polytetrafluoroethylene (PTFE) resin. Frosted glass containers have many applications in pharmacy and medicine, as well as in the fields of chemical and biological research.
