Mesh Tape 
Gypsum wallboard joint tape made with fiberglass. 

Mesne 
In between, intermediate, intervening; passing an interest from a principal to a second party and then to a third party. 

Messenger Supported Wiring 
Used in outdoor lighting systems or service drops, the electrical wiring is supported by high strength wire. 

Meta-anthracite 
High carbon content coal, which is difficult to ignite or burn; similar to graphite in composition and structure. 

Metal
High luster, heat and electricity conducting. Easily molded class of chemical element, with a crystalline structure. Very durable, they include gold, copper, iron and steel, etc. 

Metal Arc Cutting 
Use of an electric arc to provide heat to cut metal. 

Metal-clad Cable 
Rigid, flexible metal conduit with a wire bundle, consisting of individually insulated conductors covered by a flexible spiral-wound later of metal or tough paper. Also referred to as BX Cable. 

Metal-clad Switchgear
Single metal cubicle type switch, which holds all the necessary equipment to control a circuit. 

Metal Corner 
Siding trim, of metal, which has the appearance of a mitered corner. 

Metal Deck
Called Q-deck, this permanent form for concrete is made of a ribbed steel sheet for reinforcement and strength. 

Metal Drip Edge
Preformed piece of sheet metal used to protect the roof shingles from water backflow, by guiding water runoff to drip off the edge of the roof.

Metal Edge Support Clips
Also called plywood edge clips, these metal clips reach between adjacent edges of plywood panels to connect them. 

Metal Fencing
Ornamental iron or welded metal used in fences for both security and decoration. 

Metal Lath 
Screen-like structural supports for plaster or mortar, made of thin metal sheet, stretch and stamped with a pattern. 

Metal Ties 
General term used for metal strips used to connect many items. 

Metallic Paint 
Metal powder, often bronze or aluminum, added to paint to make it both reflective and increase its protectiveness. 

Metallography 
Microscopic study done to determine the quality of welds by checking cross sections carefully. Material failures are also studied to see why and how they occurred. 

Metallurgy
Scientific field of analyzing, working with and alloying metals. 

Metal Powder Cutting
Burning through metal quickly by use of a torch to produce heat and oxygen, together with an oxidizable powder, which increases the chemical reaction. 

Metal-protecting Paint 
Paint with a base of oil or oil with alkyd mixed with compounds, such as zinc chromate, which prevents rust and corrosion. 

Metal Stud 
Most often used in commercial buildings, these preformed steel framing units are galvanized or aluminum coated to protect against corrosion. Studs can range in thickness for use in non-loadbearing partitions to loadbearing parts. The metal makes the wall completely non-combustible. 

Metal Stud, Combination
Combination studs have a diagonally bent wire that is welded to rolled steel flanges and forms the web of the stud to be used to attach metal lath with wire ties or clips. 

Metal Stud, Screw 
Light gauge metal stud formed like a channel with a turned in edge and a serrated flange, to keep the screws from moving as they are installed. 

Metal Trim 
Trim, L and U shaped, used on the exposed edges of drywall for protection and an appearance of completion. 

Metamorphic Rock 
Sedimentary or igneous rock, which has undergone a change as a result of pressure, heat or chemical, making combinations of colors that, are twisted and curved to form interesting patterns. Often used as flagstone pavers, for retaining walls or siding, when cut into sections. 

Meter 
1. Measuring device for electrical current or water. 
2. Basic unit of length in the metric system, equal to 39.37 inches. 

Meter Box
Metal box, which holds the electrical meter on the wall while it measures and records usage of electricity in a building. 

Meter Pan 
Piece of equipment through which the service conductor runs. 

Meter Socket 
Receptacle for the electric power meter. 

Metes and Bounds
Land surveying method of precisely describing land by using terms of shape and boundary dimensions. 

Methane
Natural gas often used for home heating purposes. 

Metric Measure 
Decimal system of weights and measures with the basic units being: The gram (.0022046 pound) of weight. The meter (39.37 inches) of length. The liter (61.025) of capacity.

Metric Threads 
Machine threads measured in metric units. 

Metric Ton 
Metric weight which equals 1000 kilograms or 2204.62 U.S. pounds. U.S. short ton is 2000 pounds and the standard U.K. long ton is 2240 pounds. 

Metric Wrenches 
Wrenches manufactured in metric unit sizes to use with metric fasteners. 

Metropolitan Area 
Urbanized area in and around a major city. The metropolitan area may overlap county and state boundaries and may encompass a city, its suburbs, and the towns and rural areas within the orbit of its social and economic influence. 

Metropolitan Statistical Area (MSA)
One or more counties having a population of at least 50,000. A Consolidated Metropolitan Statistical Area (CMSA) is an area with two or more Primary Metropolitan Statistical Areas (PMSA). A CMSA must also include at least 1 million people. 

Mezzanine 
Balcony or low ceiling overhang just above the main floor and below the next story. In a theater, a mezzanine is the first balcony above the stage.

M-Factor 
Number that indicates the relative heat retention properties of a mass. 

MGIC 
see Mortgage Guaranty Insurance Corporation.