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Shearing (metalworking)
Shearing, also known as die cutting, is a process that cuts stock without the formation of chips or the use of burning or melting. Strictly speaking, if the cutting blades are straight the process is called shearing; if the cutting blades are curved then they are shearing-type operations.Degarmo, p. 424. The most commonly sheared materials are in the form of sheet metal or plates. However, rods can also be sheared. Shearing-type operations include blanking, piercing, roll slitting, and trimming. It is used for metal, fabric, paper and plastics. Principle A punch (or moving blade) is used to push a workpiece against the die (or fixed blade), which is fixed. Usually, the clearance between the two is 5 to 40% of the thickness of the material, but dependent on the material. Clearance is defined as the separation between the blades, measured at the point where the cutting action takes place and perpendicular to the direction of blade movement. It affects the finish of the cut ( burr) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sheet Metal
Sheet metal is metal formed into thin, flat pieces, usually by an industrial process. Thicknesses can vary significantly; extremely thin sheets are considered foil (metal), foil or Metal leaf, leaf, and pieces thicker than 6 mm (0.25 in) are considered plate, such as plate steel, a class of structural steel. Sheet metal is available in flat pieces or coiled strips. The coils are formed by running a continuous sheet of metal through a roll slitting, roll slitter. In most of the world, sheet metal thickness is consistently specified in millimeters. In the U.S., the thickness of sheet metal is commonly specified by a traditional, non-linear measure known as its Sheet metal gauge, gauge. The larger the gauge number, the thinner the metal. Commonly used steel sheet metal ranges from 30 gauge (0.40 mm) to about 7 gauge (4.55 mm). Gauge differs between ferrous (Iron, iron-based) metals and nonferrous metals such as aluminum or copper. Copper thickness, for example ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blanking (metalworking)
Blanking and piercing are shearing (metalworking), shearing processes in which a Punch (metalworking), punch and die (manufacturing), die are used to produce parts from coil or sheet stock. Blanking produces the outside features of the component, while piercing produces internal holes or shapes. The web is created after multiple components have been produced and is considered scrap material. The "slugs" produced by piercing internal features are also considered scrap. The terms "piercing" and "punching" can be used interchangeably. Die roll and burr formation Burrs and die roll are typical features of stamped components. Die roll is created when the material being stamped is compressed before the material begins to shear. Die roll takes the form of a radius around the outside edge of the blank and the pierced holes. After compression, the part shears for about 10% of the part thickness, and then fractures free of the strip or sheet. This fracturing produces a raised, jagged edge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piercing (metalworking)
Blanking and piercing are shearing processes in which a punch and die are used to produce parts from coil or sheet stock. Blanking produces the outside features of the component, while piercing produces internal holes or shapes. The web is created after multiple components have been produced and is considered scrap material. The "slugs" produced by piercing internal features are also considered scrap. The terms "piercing" and "punching" can be used interchangeably. Die roll and burr formation Burrs and die roll are typical features of stamped components. Die roll is created when the material being stamped is compressed before the material begins to shear. Die roll takes the form of a radius around the outside edge of the blank and the pierced holes. After compression, the part shears for about 10% of the part thickness, and then fractures free of the strip or sheet. This fracturing produces a raised, jagged edge which is called a "burr". Burrs are typically removed by tumbling ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Roll Slitting
Roll slitting is a shearing (metalworking), shearing operation that cuts a large roll of material into narrower rolls. There are two types of slitting: log slitting and rewind slitting. In log slitting the roll of material is treated as a whole (the 'log') and one or more slices are taken from it without an unrolling/re-reeling process. In rewind slitting the web is unwound and run through the machine, passing through knives or lasers, before being rewound on one or more shafts to form narrower rolls. The multiple narrower strips of material may be known as ''mults'' (short for multiple) or ''pancakes'' if their diameter is much more than their width. For log slitting, the machine used is called a paper sawing machine or a paper roll saw, which typically uses a circular saw or band saw to cut rolls into narrower ones. For rewind slitting the machine used is called a slitter rewinder, a slitter or a slitting machine – these names are used interchangeably for the same machines. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Burr (metal)
A burr is a raised edge or small piece of material that remains attached to a workpiece after a modification process. It is usually an unwanted piece of material and is removed with a deburring tool in a process called deburring. Burrs are most commonly created by machining operations, such as grinding, drilling, milling, engraving or turning. It may be present in the form of a fine wire on the edge of a freshly sharpened tool or as a raised portion of a surface; this type of burr is commonly formed when a hammer strikes a surface. Deburring accounts for a significant portion of manufacturing costs. In the printmaking technique of drypoint, burr, which gives a rich fuzzy quality to the engraved line, is highly desirable—the great problem with the drypoint medium is that the burr rapidly diminishes after as few as ten impressions are printed. Types There are three types of burrs that can be formed from machining operations: ''Poisson burr'', ''rollover burr'', and ''breakout ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Power Consumption
Electric energy consumption is energy consumption in the form of electrical energy. About a fifth of global energy is consumed as electricity: for residential, industrial, commercial, transportation and other purposes. The global electricity consumption in 2022 was 24,398 terawatt-hour (TWh), almost exactly three times the amount of consumption in 1981 (8,132 TWh). China, the United States, and India accounted for more than half of the global share of electricity consumption. Japan and Russia followed with nearly twice the consumption of the remaining industrialized countries. Overview Electric energy is most often measured either in joules (J), or in watt hours (W·h). : 1 W·s = 1 J : 1 W·h = 3,600 W·s = 3,600 J : 1 kWh = 3,600 kWs = 1,000 Wh = 3.6 million W·s = 3.6 million J Electric and electronic devices consume electric energy to generate desired output (light, heat, motion, etc.). During operation, some part of the energy is lost depending on the electrical efficien ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shear Stress
Shear stress (often denoted by , Greek alphabet, Greek: tau) is the component of stress (physics), stress coplanar with a material cross section. It arises from the shear force, the component of force vector parallel to the material cross section. ''Normal stress'', on the other hand, arises from the force vector component perpendicular to the material cross section on which it acts. General shear stress The formula to calculate average shear stress or force per unit area is: \tau = ,where is the force applied and is the cross-sectional area. The area involved corresponds to the material face (geometry), face parallel to the applied force vector, i.e., with surface normal vector perpendicular to the force. Other forms Wall shear stress Wall shear stress expresses the retarding force (per unit area) from a wall in the layers of a fluid flowing next to the wall. It is defined as:\tau_w := \mu\left.\frac\_,where is the dynamic viscosity, is the flow velocity, and is the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shear Strength
In engineering, shear strength is the strength of a material or component against the type of yield or structural failure when the material or component fails in shear. A shear load is a force that tends to produce a sliding failure on a material along a plane that is parallel to the direction of the force. When a paper is cut with scissors, the paper fails in shear. In structural and mechanical engineering, the shear strength of a component is important for designing the dimensions and materials to be used for the manufacture or construction of the component (e.g. beams, plates, or bolts). In a reinforced concrete beam, the main purpose of reinforcing bar (rebar) stirrups is to increase the shear strength. Equations For shear stress \tau applies :\tau = \frac , where :\sigma_1 is major principal stress and :\sigma_3 is minor principal stress. In general: ductile materials (e.g. aluminum) fail in shear, whereas brittle materials (e.g. cast iron) fail in tension . ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deformation (engineering)
In engineering, deformation (the change in size or shape of an object) may be ''elastic'' or ''plastic''. If the deformation is negligible, the object is said to be ''rigid''. Main concepts Occurrence of deformation in engineering applications is based on the following background concepts: * ''Displacements'' are any change in position of a point on the object, including whole-body translations and rotations ( rigid transformations). * ''Deformation'' are changes in the relative position between internals points on the object, excluding rigid transformations, causing the body to change shape or size. * ''Strain'' is the ''relative'' ''internal'' deformation, the dimensionless change in shape of an infinitesimal cube of material relative to a reference configuration. Mechanical strains are caused by mechanical stress, ''see stress-strain curve''. The relationship between stress and strain is generally linear and reversible up until the yield point and the deformation is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Low Alloy Steel
Alloy steel is steel that is alloyed with a variety of elements in amounts between 1.0% and 50% by weight, typically to improve its mechanical properties. Types Alloy steels divide into two groups: low and high alloy. The boundary between the two is disputed. Smith and Hashemi define the difference at 4.0%, while Degarmo, ''et al.'', define it at 8.0%. Most alloy steels are low-alloy. The simplest steels are iron (Fe) alloyed with (0.1% to 1%) carbon (C) and nothing else (excepting slight impurities); these are called carbon steels. However, alloy steel encompasses steels with additional (metal) alloying elements. Common alloyants include manganese (Mn) (the most common), nickel (Ni), chromium (Cr), molybdenum (Mo), vanadium (V), silicon (Si), and boron (B). Less common alloyants include Aluminium (Al), cobalt (Co), copper (Cu), cerium (Ce), niobium (Nb), titanium (Ti), tungsten (W), tin (Sn), zinc (Zn), lead (Pb), and zirconium (Zr). Properties Alloy steels vari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alligator Shear
An alligator shear, historically known as a lever shear and sometimes as a crocodile shear, is a metal-cutting shearing (metalworking), shear with a hinged jaw, powered by a flywheel or hydraulic cylinder. Alligator shears are generally set up as stand-alone shears; however, there are types for excavators. The jaw size can range from long. They are generally used to cut ferrous members, such as rebar, pipe (material), pipe, angle iron, or I-beams... Operation Older alligator shears were powered by a flywheel. These shears ran continuously, which posed a safety hazard. Now alligator shears are hydraulic actuator, hydraulically actuated. When actuated, the piston arm extends and slowly closes the upper jaw of the alligator shear, which passes alongside the bed or lower jaw of the shear to perform the cut. Uses Alligator shears are used for cutting long metal stock or scrap, generally where accuracy is not an important consideration, and the size or shape of the material makes othe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shear (sheet Metal)
There are many types of shears used to shear or cut sheet metal. Types Alligator shear An alligator shear, historically known as a lever shear and sometimes as a crocodile shear, is a metal-cutting shear with a hinged jaw, powered by a flywheel or hydraulic cylinder. Alligator shears are generally set up as stand-alone shears; however, there are types for excavators. The jaw size can range from 4 to 36 in (100 to 910 mm) long. They are generally used to cut ferrous members, such as rebar, pipe, angle iron, or I-beams. Bench shear A ''bench shear'', also known as a ''lever shear'', is a bench mounted shear with a compound mechanism to increase the mechanical advantage. It is usually used for cutting rough shapes out of medium-sized pieces of sheet metal, but cannot do delicate work. For the small shear, it mostly designed for a wide field of applications. Light weight and easy efficient operation, yet very sturdy in construction. The cutting blades fitted are carefully and accur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
