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Machine Tool 101

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[Machine Tools 101] There are 11 common tools and processes that you'll see in almost any marine workshop. For any work in a marine workshop, the baseline of necessary safety equipment is safety glasses and gloves although for many processes, additional equipment is necessary. Any machine part, function or process which may cause injury must be safeguarded through protective clothing, equipment, or procedures. Typically, danger points of a machine are where it performs its action such as cutting, shaping or boring. The components of the mechanical system which transmits energy to the part of the machine performing the work such as pulleys, belts, chains or gears or other moving parts. Therefore, any safeguard must prevent contact from these danger points. [Safeguards Shield the danger point from falling objects] It also should shield the danger point from falling objects, [Avoid interference with the function of the machine] avoid interference with the function of the machine, [Create no new hazards] and create no new hazards. [Welding] Perhaps the most common workshop process is welding. Welding is used to join two metals. There are a number of welding techniques but the one most commonly used in maritime applications is electric arc welding. In this process, an enormous amount of electricity is used to heat up the two edges then filler material is placed in between to join them. [>3000 °F (1,648.89 °C)] This process requires a flame temperature of over 3,000 degrees Fahrenheit. The advantage of welding is that it creates an immensely strong bond. Since the two pieces of material essentially become one, the bond is just as strong as the materials themselves. Welding is a potentially dangerous process if done without proper precautions. [Dangers of Welding Eye Damage, Burns, Electrocution Toxic Fumes Fire] Dangers of welding include eye damage, burns, electrocution, toxic fumes and fire. [Brazing] Another way of joining metals is brazing. With brazing, the joint is heated, then a brazing rod is melted against the hot joint. The two materials can be two different types of metal, or even non-metal since they are not melted themselves. The advantage of brazing is that your filler can be a metal or metal alloy [Copper: 1,984 °F (1,084 °C) Silver: 1,763 °F (926 °C) Aluminum: 1,218 °F (659 °C)] with a much lower melting point, although the joint is typically not as strong as a weld. [Gas Cutting] Gas cutting, also known as oxy-fuel cutting, is the most commonly used cutting process on ships. It allows a machinist to cut through thick metals with relative ease. It works by heating up a metal material to near its melting point, so it's soft and malleable. A stream of high purity oxygen is then introduced which oxidizes or burns the super-heated metal, creating a clean cut. [Annealing] Annealing is a process that rearranges the physical and chemical properties of a material in order to soften it for work. The metal is heated until it is glowing bright orange and then is cooled in a controlled and consistent manner so that the atoms rearrange into a more organized pattern. This helps reduce internal stress and improves ductility. [Riveting] Riveting is another process used to hold two pieces of metal together. A small rivet is heated until it's soft and malleable. It then is pushed through a prepared hole in both pieces of metal. A worker hammers the side without a head in order to expand it. Then, as it cools, the rivet shrinks which tightens the two pieces of metal together. One advantage of riveting is that it is a relatively easy and safe process which can be done my less specialized laborers. It's also much easier to identify a damaged joint with rivets than with welding. [Lathe] A lathe is a piece of machinery commonly found in marine workshops that rotates a piece of material at a high speed which is then formed by a stationary cutting tool into a part. A lathe is an expensive piece of machinery but they do quickly and automatically make precise parts which for a ship, is much more efficient than stocking all necessary parts at sea. Since the lathe rotates at a high speed, it is important that the operator does not wear any loose or baggy clothing that could be caught in the machine. [Drilling] Drilling is the process of cutting a hole in a material. This is done by rotating a drill bit at high speed and forcing it down into the material. As the drill bit rotates, it chips away at the material, therefore creating a hole. With this process, the drill bit always needs to be stronger than the material drilled into. [High-Speed Steel Cobalt Steel Tungsten Carbide] So these bits are often made of high-speed steel, cobalt steel or tungsten carbide. [Grinding] Grinding is a process used to finish and cut a material precisely and uniformly. The grinding wheel, which rotates at a very high speed, is slightly coarse so that it cuts part of the material away each time it passes over. In the end, this produces a material with a smooth and clean finish on the outside. [Buffing] Buffing is a similar process to grinding but it is only used to change the appearance of the material. With buffing, no material is removed from the surface. It only removes debris from the materials surface. [Tap] A tap is a tool used to create the threads in a drill hole so that a screw can be used. It can also be used to reform the threads in a damaged hole. Tapping can be done by hand, with a drill or on a lathe. [Thread Extractor] A thread extractor is a tool that also goes on the end of a drill. It is used to remove a screw with a broken or malformed head from its hole. The threads on a thread extractor run the opposite direction from the threads so that when turned, the thread extractor will rotate the screw out. Each of these processes has a unique dangers that must be avoided and every company has a slightly different safety management system. So be sure that you know the required regulations and personal protective equipment for your company before starting any job.

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Duration: 5 minutes and 36 seconds
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Language: English
License: Dotsub - Standard License
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Views: 6
Posted by: maritimetraining on Apr 17, 2018

Machine Tool 101

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