Trepanning is used for larger hole diameters and where machine power is limited, because it is not as powerconsuming as solid drilling. It is commonly used for creating larger diameter holes (up to 915 mm (36.0 in)) where a standard drill bit is not feasible or economical.
Trepanning. Trepanning is used for larger hole diameters and where machine power is limited, because it is not as powerconsuming as solid drilling. The trepanning tool does not machine the whole diameter, only a ring at the periphery 10 most extreme places on Earth. Trepanning refers to a specialized form of surgery involving drilling or scraping a hole into the skull. The goal of trepanning is to expose the tough and inflexible dura mater, or pachymeninx, which is the outermost layer of the meninges surrounding the brain and spinal cord. The tools commonly used in trepanning included a sharp knife, which was used to cut through the skin of the skull and made it possible to pull back the flaps, and a borer similar to a corkscrew. Surgeons also used brushes and files to tidy up the final area around the hole. 347. Just wanted to post an explanation what trepanning is. Trepanning is a manufacturing process used to produce holes or circular grooves by using one or more cutters and revolving them around a center. Trepanning machining is used to produce the following features and parts: •Disks from flat stock.  Trepanning Manufacturing Basics. Trepanning is a manufacturing process used to produce holes or circular grooves by using one or more cutters and revolving them around a center. Trepanning machining is used to produce the following features and parts: 1  Low volume disks from flat stock. 2  Large diameter through holes in flat stock. 3  Machining internal and external circular grooves or o-ring glands. 4  Deep holes 2 (50.8mm) or more in diameter. Among New World societies trepanning is most commonly found in the Andean civilizations such as the pre-Incan cultures, for example the Paracas culture Ica situated in what now is Ica located South of Lima. It has also been found in the Muisca Confederation (in modern-day Colombia) and the Inca Empire. There is some contemporary use of the term. In modern eye surgery, a trephine instrument is used in corneal transplant surgery. The procedure of drilling a hole through a fingernail or toenail is also known as trephination. During the Greek age, Hippocrates taught trepanning. There is evidence that trepanation was used as a cure for migraines. Trepanning is a type of surgery that involves drilling a small hole into the skull. The tools commonly used in trepanning included a sharp knife, which was used to cut through the skin of the skull and made it possible to pull back the flaps, and a borer similar to a corkscrew. Surgeons also used brushes and files to tidy up the final area around the hole. Trepanation. Trepanation. Trepanning is one of the oldest recorded surgical procedures and has been documented world wide. Although trepanning was used over many time periods, the procedure was first used in the Stone Age. Researchers have found evidence of trepanation used in North America, South America, Africa, and Europe (Missios, 2007). Trepanation in North America:  Trepanning is commonly used for creating larger diameter holes (up to 915 mm (36.0 in)) where a standard drill bit is not feasible or economical. Trepanning removes the desired diameter by cutting out a solid disk similar to the workings of a drafting compass. Drilling is a cutting process that uses a drill bit to cut or enlarge a hole of circular cross-section in solid materials. The drill bit is a rotary cutting tool, often multipoint. The bit is pressed against the workpiece and rotated at rates from hundreds to thousands of revolutions per minute.
http://www.sandvik.coromant.com/en-gb/knowledge/drilling/application_overview/dedicated_methods/trepanning/pages/default.aspx http://www.wisegeek.com/what-is-trepanning.htm http://www.practicalmachinist.com/vb/south-bend-lathes/question-about-trepanning-214218/ http://engineersedge.com/manufacturing/trepanning-machining.htm https://en.wikipedia.org/wiki/Trepanning http://www.wisegeek.com/what-is-trepanning.htm http://mentalillness.umwblogs.org/stone-age/trepanation/ https://en.wikipedia.org/wiki/Trepanning_(manufacturing)
what is trepanning used for