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Fishtail Gauge
Center gauges and fishtail gauges are gauges used in lathe work for checking the angles when grinding the profiles of single-point screw-cutting tool bits and centers. In the image, the gauge on the left is called a fishtail gauge or center gauge, and the one on the right is another style of center gauge. These gauges are most commonly used when hand-grinding threading tool bits on a bench grinder, although they may be used with tool and cutter grinders. When the tool bit has been ground to the correct angle, they are then used to set the tool perpendicular to the workpiece. They can incorporate a range of sizes and types on the one gauge, the two most common being metric or UNC and UNF at 60°, and BSW at 55°. Gauges also exist for the Acme thread form Trapezoidal thread forms are screw thread profiles with trapezoidal outlines. They are the most common forms used for leadscrews (power screws). They offer high strength and ease of manufacture. They are typically found ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gauge (engineering)
A gauge, in science and engineering, is a device used to make measurements or in order to display certain dimensional information. A wide variety of tools exist which serve such functions, ranging from simple pieces of material against which sizes can be measured to complex pieces of machinery. Depending on usage, a gauge can be described as "a device for measuring a physical quantity",Richard Talman, ''Geometric Mechanics'' (2008), p. 255-56: "a "gauge" is a device for measuring a physical quantity—a thermometer is a temperature gauge, a ruler is a length gauge".. for example "to determine thickness, gap in space, diameter of materials, or pressure of flow",Ray Herren, ''Agricultural Mechanics: Fundamentals & Applications'' (2009), p. 109: "A gauge is a device used to determine thickness, gap in space, diameter of materials, or pressure of flow". or "a device that displays the measurement of a monitored system by the use of a needle or pointer that moves along a calibrated scale" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Screw Thread
A screw thread, often shortened to thread, is a helical structure used to convert between rotational and linear movement or force. A screw thread is a ridge wrapped around a cylinder or cone in the form of a helix, with the former being called a ''straight'' thread and the latter called a ''tapered'' thread. A screw thread is the essential feature of the screw as a simple machine and also as a threaded fastener. The mechanical advantage of a screw thread depends on its ''lead'', which is the linear distance the screw travels in one revolution. In most applications, the lead of a screw thread is chosen so that friction is sufficient to prevent linear motion being converted to rotary, that is so the screw does not slip even when linear force is applied, as long as no external rotational force is present. This characteristic is essential to the vast majority of its uses. The tightening of a fastener's screw thread is comparable to driving a wedge into a gap until it sticks fast thro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tool Bit
A tool bit is a non-rotary cutting tool used in metal lathes, shapers, and planers. Such cutters are also often referred to by the set-phrase name of single-point cutting tool, as distinguished from other cutting tools such as a saw or water jet cutter. The cutting edge is ground to suit a particular machining operation and may be resharpened or reshaped as needed. The ground tool bit is held rigidly by a tool holder while it is cutting. Geometry Back rake is to help control the direction of the chip, which naturally curves into the work due to the difference in length from the outer and inner parts of the cut. It also helps counteract the pressure against the tool from the work by pulling the tool into the work. Side rake along with back rake controls the chip flow and partly counteracts the resistance of the work to the movement of the cutter and can be optimized to suit the particular material being cut. Brass for example requires a back and side rake of 0 degrees whil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lathe Center
A lathe center, often shortened to center, is a tool that has been ground to a point to accurately position a workpiece on an axis. They usually have an included angle of 60°, but in heavy machining situations an angle of 75° is used. The primary use of a center is to ensure concentric work is produced; this allows the workpiece to be transferred between machining (or inspection) operations without any loss of accuracy. A part may be ''turned'' in a lathe, sent off for hardening and tempering and then ground ''between centers'' in a cylindrical grinder. The preservation of concentricity between the turning and grinding operations is crucial for quality work. When turning between centres, a steady can be used to support longer workpieces where the cutting forces would deflect the work excessively, reducing the finish and accuracy of the workpiece, or creating a hazardous situation. A center lathe has applications anywhere that a ''centered'' workpiece may be used; this is not ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bench Grinder
A bench grinder is a benchtop type of grinding machine used to drive abrasive wheels. A pedestal grinder is a similar or larger version of grinder that is mounted on a pedestal, which may be bolted to the floor or may sit on rubber feet. These types of grinders are commonly used to hand grind various cutting tools and perform other rough grinding. Depending on the bond and grade of the grinding wheel, it may be used for sharpening cutting tools such as tool bits, drill bits, chisels, and gouges. Alternatively, it may be used to roughly shape metal prior to welding or fitting. A wire brush wheel or buffing wheels can be interchanged with the grinding wheels in order to clean or polish workpieces. Stiff buffing wheels can also be used when deburring is the task at hand. Some buffing machines (buffers) are built on the same concept as bench grinders except for longer housings and arbors with buffing wheels instead of grinding wheels. Bench grinders are standard equipment in met ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tool And Cutter Grinder
A Tool and Cutter Grinder is used to sharpen milling cutters and tool bits along with a host of other cutting tools. It is an extremely versatile machine used to perform a variety of grinding operations: surface, cylindrical, or complex shapes. The image shows a manually operated setup, however highly automated Computer Numerical Control (CNC) machines are becoming increasingly common due to the complexities involved in the process. The operation of this machine (in particular, the manually operated variety) requires a high level of skill. The two main skills needed are understanding of the relationship between the grinding wheel and the metal being cut and knowledge of tool geometry. The illustrated set-up is only one of many combinations available. The huge variety in shapes and types of machining cutters requires flexibility in usage. A variety of dedicated fixtures are included that allow cylindrical grinding operations or complex angles to be ground. The vise shown can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perpendicular
In elementary geometry, two geometric objects are perpendicular if they intersect at a right angle (90 degrees or π/2 radians). The condition of perpendicularity may be represented graphically using the ''perpendicular symbol'', ⟂. It can be defined between two lines (or two line segments), between a line and a plane, and between two planes. Perpendicularity is one particular instance of the more general mathematical concept of '' orthogonality''; perpendicularity is the orthogonality of classical geometric objects. Thus, in advanced mathematics, the word "perpendicular" is sometimes used to describe much more complicated geometric orthogonality conditions, such as that between a surface and its '' normal vector''. Definitions A line is said to be perpendicular to another line if the two lines intersect at a right angle. Explicitly, a first line is perpendicular to a second line if (1) the two lines meet; and (2) at the point of intersection the straight angle on one side ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unified Thread Standard
The Unified Thread Standard (UTS) defines a standard thread form and series—along with allowances, tolerances, and designations—for screw threads commonly used in the United States and Canada. It is the main standard for bolts, nuts, and a wide variety of other threaded fasteners used in these countries. It has the same 60° profile as the ISO metric screw thread, but the characteristic dimensions of each UTS thread (outer diameter and pitch) were chosen as an inch fraction rather than a millimeter value. The UTS is currently controlled by ASME/ANSI in the United States. Origins : ''See the "History of standardization" section of the screw thread article.'' Basic profile Each thread in the series is characterized by its major diameter ''D''maj and its pitch, ''P''. UTS threads consist of a symmetric V-shaped thread. In the plane of the thread axis, the flanks of the V have an angle of 60° to each other. The outermost and the innermost of the height ''H'' of the V-sha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
British Standard Whitworth
British Standard Whitworth (BSW) is an imperial-unit-based screw thread standard, devised and specified by Joseph Whitworth in 1841 and later adopted as a British Standard. It was the world's first national screw thread standard, and is the basis for many other standards, such as BSF, BSP, BSCon, and BSCopper. History The Whitworth thread was the world's first national screw thread standard, devised and specified by Joseph Whitworth in 1841. Until then, the only standardization was what little had been done by individual people and companies, with some companies' in-house standards spreading a bit within their industries. Whitworth's new standard specified a 55° thread angle and a thread depth of 0.640327''p'' and a radius of 0.137329''p'', where ''p'' is the pitch. The thread pitch increases with diameter in steps specified on a chart. The Whitworth thread system was later to be adopted as a British Standard to become British Standard Whitworth (BSW). An example of the us ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acme Thread Form
Trapezoidal thread forms are screw thread profiles with trapezoidal outlines. They are the most common forms used for leadscrews (power screws). They offer high strength and ease of manufacture. They are typically found where large loads are required, as in a vise or the leadscrew of a lathe. Standardized variations include multiple-start threads, left-hand threads, and self-centering threads (which are less likely to bind under lateral forces). The original trapezoidal thread form, and still probably the one most commonly encountered worldwide, with a 29° thread angle, is the Acme thread form ( ). The Acme thread was developed in 1894 as a profile well suited to power screws that has various advantages over the square thread,See: * Simpson, John and Proffitt, Michael, ed.s, "acme", ''Oxford English Dictionary: Additions Series'', vol. 3 (Oxford, England: Oxford University Press, 1997)p. 10.* The Acme thread was proposed by Albert Man Powell, then president of the Powell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
