Main Page | See live article | Alphabetical index Manual Metal Arc welding, also known as stick or MMA welding is one of the commonest forms of welding. An electric current (either alternating current or direct current) is used to form an arc between an electrode coated in flux and the metals to be joined. The flux gives off gases to prevent oxygen reacting with the weld metal. The flux then solidifies to form slag on top of the weld. Once cool the slag can easily be chipped off. MMA welding takes a lot of manual dexterity in order to be able to make good welds. Flat welds are easiest, but skilled welders can do vertical or overhead welding. The most skilled welders undertake joints in high pressure pipess which require a continuous transition between the various welding techniques. Relatively small, low-cost versions of arc welding equipment are available for the amateur hobbyist or non-expert; for instance, farmers often own this type of welder. Other forms of welding are usually out of the financial reach of the amateur. This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.