Abstract: A solder removal apparatus is provided. The solder removal apparatus comprises a plurality of solder-interfacing protrusions extending from a body by a length. Each of the plurality of solder-interfacing protrusions is configured to remove a corresponding one of a plurality of solder features from a semiconductor device, where each of the plurality of solder features has a height and an amount of solder material.

Abstract: A method includes obtaining multiple components to be coupled together, such as during a brazing operation. At least one of the multiple components includes a stop-off. The stop-off includes one or more markings formed on at least one surface of the at least one component. The one or more markings include (i) one or more etches in the at least one surface and/or (ii) one or more oxides formed by localized heating of the at least one surface. The method also includes coupling the multiple components together using a melted or liquid material, such as a filler metal used in the brazing operation. The stop-off controls or interrupts a flow of the melted or liquid material in a joint between the multiple components during the coupling. The one or more markings could interfere with a capillary action that pulls the melted or liquid material into the joint.

Abstract: A mobile hardbanding system that uses PTA welding to perform hardbanding on drill string sections at the well site. The inventive system allows alternate use of PTA and MIG welding. Both a PTA torch and a MIG torch are provided. Changing from one type of welding to the other is simplified by including separate electrical, gas, and cooling conduits for each torch. The torch not in use is parked in the welding compartment near the weld box. The powder hopper for the PTA welding assembly may be mounted on a swivel arm so that it can be moved out of the way when the MIG torch is in use.

Abstract: A method of managing welding data, including receiving, via a network, welding data from a data storage system, populating, via a processor, a user viewable dashboard page with one or more user input controls, receiving a user input via the user viewable dashboard page, and populating, via the processor, the user viewable dashboard page with graphical indicia representative of one or more subsets of welding data corresponding to the received user input. The welding data includes welding parameters associated with welding sessions performed by a plurality of welding operators. The user input controls include filter criteria, a search control, or any combination thereof. Each filter criterion of the filter criteria corresponds to a respective subset of the welding data. The user input includes a selection of one or more filter criteria from a user, a search string input via the search control, or any combination thereof.

Abstract: A system and method for generating a weld are provided. The system receives a selection of a magnitude of a voltage. The system selects a first weld control algorithm when the magnitude of the voltage is in a first range of values. The system may also select a second weld control algorithm when the magnitude of the voltage is in a second range of values. The system may generate welding output power based on the first and second weld control algorithms.

Abstract: A welding-type system with a programmed controller and alert devices for alerting a user as to the impending thermal shutdown of the welding-type system.

Abstract: A joule-heating press and method for manufacturing a metallic honeycomb core via diffusion bonding. The method may include printing a pattern of strips of a stop-off material to surfaces of a plurality of sheets of metal at locations where diffusion bonding is not desired and stacking the sheets of metal together in a sequence for forming the honeycomb core. Then the method may include steps of pressing the sheets of metal together between two press plates made of conductive material and applying electric current to the conductive material of the press plates. This allows current to flow through a thickness of the sheets of metal and the sheets of metal are thereby diffusion bonded to each other via joule heating at locations absent the stop-off material. Finally, the method may include a step of expanding the sheets of metal into the honeycomb core.

Abstract: A first electrode coolant path is configured to cool a first welding electrode by liquid coolant flowing from a supply path through the first electrode coolant path to a return path. A second electrode coolant path is configured to cool a second welding electrode by liquid coolant flowing from the supply path through the second electrode coolant path to the return path. Three or more valves are configured to stop or reduce liquid coolant flow through the first or second electrode coolant path and configured to stop or reduce liquid coolant backflow from the return path when the first or second welding electrode is at least partially detached. At least one valve is coupled in the first or second electrode coolant path. A drawback apparatus generates a suction force to draw liquid coolant away from a gap formed when the first or second welding electrode is at least partially detached.

Abstract: To provide a welding gun capable of improving the durability by effectively bearing the load in the thrust direction, and capable of providing a heavyweight and large-sized movable gun arm, even in a small-sized main body unit. A welding gun 10 of a guide groove type is provided with a thrust direction guide mechanism including: two guide pins 19a and 19b provided to an arm holder 13 in an integrated manner by penetrating first and second guide grooves 17a and 17b; brackets 23a and 23b being fixedly provided to the end portions of the guide pins 19a and 19b, and having a length sufficient to traverse the first and second guide grooves 17a and 17b in a direction orthogonal to the axis line of the guide pins 19a and 19b; and thrust bearing members 24a and 24b being provided to the end portions of the brackets 23a and 23b, abutting on a side plate 11a of a gun body 11, so as to be movable along the first and second guide grooves 17a and 17b.

Abstract: A method includes the following: an incidence step in which ultrasonic waves from an insertion side and the side opposite thereto of a tool are caused to be incident on a joint part when a workpiece is joined by the tool that has a probe and a shoulder which supports the probe and that is for friction stir welding; an image acquisition step for obtaining an ultrasonic wave transmission image of the joint part using the ultrasonic waves; and a determination step for determining that the joint part has been joined if width-dimensions of the joint part obtained from the ultrasonic wave transmission image are equivalent to at least the outer diameter d of the probe and if no defect of a prescribed size or greater is found in a range equivalent to the outer diameter D of the shoulder or less in the ultrasonic wave transmission image.

Abstract: A method of making an aerospace component such as a spar for an aircraft wing is disclosed. The method includes placing two billets of different alloy in abutting relation, there being no voids or channels formed therebetween, partial penetration friction stir welding together the two billets from opposing sides of the billets, the welds so formed being separated by a central region formed partly by one billet and partly by the other billet, and then machining away material. The machining may be performed so as to leave no portion having a partial penetration friction stir weld, so as to remove all of the central region, and so as to form a multi-alloy spar having at least one transverse web section having a slot formed at least in part by the removal of the central region.

Abstract: A bonded dissimilar material structure includes a first component made of a first dissimilar material; a second component made of a second dissimilar material stacked under the first component; and a plurality of blind holes formed on an upper surface of the second component; and the first component has a plurality of protrusions formed in the plurality of blind holes on the second component, respectively.

Abstract: A series of laser pulse bundles or bursts are used for micromachining target structures. Each burst includes short laser pulses with temporal pulse widths that are less than approximately 1 nanosecond. A laser micromachining method includes generating a burst of laser pulses and adjusting an envelope of the burst of laser pulses for processing target locations. The method includes adjusting the burst envelope by selectively adjusting one or more first laser pulses within the burst to a first amplitude based on processing characteristics of a first feature at a target location, and selectively adjusting one or more second laser pulses within the burst to a second amplitude based on processing characteristics of a second feature at the target location. The method further includes directing the amplitude adjusted burst of laser pulses to the target location.

Abstract: A method controls an operation of a laser processing machine with redundant actuators including a first actuator and a second actuator. The method determines a feasible region for states of the first actuator and states of a reference trajectory of the first actuator defined by constraints of the laser processing machine, constraints on the reference trajectory and constraints on a range of motion of the second actuator. The method selects a subset of the feasible region, such that for any state of the first actuator and any state of the reference trajectory within the subset, there is an admissible control maintaining the state of the first actuator within the subset of the feasible region for admissible future states of the reference trajectory, and selects an admissible control action for controlling the operation such that the state of the first actuator remains in the subset of the feasible region.

Abstract: A gas flow can be provided together with a liquid jet guided laser beam to remove accumulated liquid on the processing surface. The gas flow can have minimum interference with the liquid jet guided laser beam, while functions to blow away liquid generated by the liquid jet. Keeping the surface free from accumulated liquid can improve the efficiency of the liquid jet guided laser processing.

Abstract: A method of manufacturing a tube, and a tube, the method comprising the steps of: coupling in position a first tube body and a second tube body by inserting a first insert portion of a connecting pin into an end portion of a first hole of the first tube body and inserting a second insert portion into an end portion of a first hole of the second tube body; welding all around an outer circumferential portion of the coupled portion of the first tube body and the second tube body and all around an inner circumferential portion of the first holes in which the connecting pin is inserted; and removing the connecting pin remaining inside the first hole of the first tube body and the first hole of the second tube body.

Abstract: A method of producing a semiconductor chip, including the following steps (a) to (d): (a) a step of, in the state of having laminated a mask-integrated surface protective tape on the side of a patterned surface of a semiconductor wafer, grinding the backing-face of the semiconductor wafer; laminating a wafer fixing tape on the backing-face side of the ground semiconductor wafer; and supporting and fixing the wafer to a ring flame; (b) a step of, after peeling the surface protective tape thereby to expose the mask material layer on top, forming an opening of a street of the semiconductor wafer; (c) a plasma dicing step of segmentalizing the semiconductor wafer by a plasma irradiation to singulate it into semiconductor chips; and (d) an ashing step of removing the mask material layer by the plasma irradiation.

Abstract: An apparatus for cutting a substrate comprises first and second lasers, and first and second optical fibers each having an input end and an output end opposite to the input end, wherein the input ends of the first and second optical fibers are connected to the first and second lasers respectively. The output ends of the first and second optical fibers are movable relative to the substrate and are configured to image first and second laser beams onto the substrate simultaneously for cutting the substrate.

Abstract: In order to improve the strength and elongation of a solder and improve the reliability of a joining portion joined by the solder, the present invention provides a solder alloy that comprises 2.0 to 4.0 mass % of Ag, 0.5 to 1.0 mass % of Cu, 0.1 to 0.5 mass % of an additive element selected from the group consisting of Ca and Mn, and a balance of Sn.

Abstract: The present invention provides an aluminum alloy brazing sheet for electric resistance welding, which has high strength while being thinned and can reduce the occurrence of welding defects in the electric resistance welding. Disclosed is an aluminum alloy brazing sheet for electric resistance welding, including a core layer and a brazing filler layer cladded on at least one surface of the core layer, wherein the brazing filler layer is made of an aluminum alloy comprising Si: 5.5 to 12.0% by mass, and at least one of Na: 0.0003 to 0.0030% by mass and Sr: 0.0020 to 0.1000% by mass, with the balance being Al and inevitable impurities, wherein the brazing filler layer in a molten state at 650° C. exhibits a viscosity of 0.01 Pa·s or less.

Abstract: An aluminum alloy brazing sheet achieves a stable brazability equal to by brazing using a flux, even if an etching treatment is not performed on the brazing site. The aluminum alloy brazing sheet is used to braze aluminum in an inert gas atmosphere without using a flux and includes a core material and a filler metal, one side or each side of the core material being clad with the filler metal, the core material being formed of an aluminum alloy that includes 0.2 to 1.3 mass % of Mg, the filler metal including 6 to 13 mass % of Si and 0.004 to 0.1 mass % of Li, with the balance being aluminum and unavoidable impurities, a surface oxide film having been removed from the brazing sheet, and an oil solution that decomposes when heated at 380° C. or less in an inert gas having been applied to the brazing sheet.

Abstract: In one aspect, a device with dynamic optical properties comprises a fluid transfer component comprising a polymer film with one or more layers; an active region of the fluid transfer component comprising a plurality of fluid channels defined by one or more interior surfaces within the polymeric film. In one embodiment, each fluid channel comprises at least 1 row of fluid channels in a thickness direction of the polymeric film. Each fluid channel comprises a first fluid with a first optical property and the active region has a first optical state, and when the a flow source generates fluid flow for a second fluid with a second optical property different from the first optical property to flow through the fluid channels in the active region, the optical state of the active region changes from a first optical state to a second optical state different from the first optical state.

Abstract: A crimping system of a fastening component onto a support, including a crimping tool comprising a housing and a traction rod configured to cooperate with the fastening component so as to deform the fastening component when a translation of the traction rod takes place, a fluid source connected to the housing to supply a fluid under pressure to move the traction rod, a sensor to measure the movements of the traction rod, a detector to provide a pressurisation information of the fluid in the housing, and a control unit configured to record a curve of the measured movements and the pressurisation information of the fluid in the housing.

Abstract: A method of assembling an annular combustion chamber assembly comprises positioning a plurality of first combustion chamber segments circumferentially side by side to form an annulus and removably securing the downstream end of each first combustion chamber segment to a first ring to form a first assembly. The method comprises positioning a plurality of second combustion chamber segments circumferentially side by side to form an annulus, removably securing the downstream end of each second combustion chamber segment to a second ring to form a second assembly. The method comprises removably securing the upstream end of each second combustion chamber segment of the second assembly to an annular upstream end wall. The method comprises inserting the second assembly into the first assembly and then removably securing the upstream end of each first combustion chamber segment of the first assembly to the annular upstream end wall to form the annular combustion chamber assembly.

Abstract: The present invention relates to a method for sealing a heat transfer unit, which includes the steps of providing a heat transfer unit having at least one opening, welding the opening to form a welding section and close the opening, and pinching off the welding section and cutting part of the welding section to form a cutting end and complete sealing the opening of the heat transfer unit. By means of the method of the present invention, an extremely short dead zone can be obtained and high heat conduction efficiency is enhanced, further having the effects of reducing the arrangement space and shrinking steps of the heat pipe.

Abstract: The invention relates to pallet changers and methods for processing sheet-like materials with at least two movably arranged pallets movably positioned in a main frame and having a support surface for receiving a sheet-like material. The pallets are moved in alternation with a drive from the main frame into a material processing machine and back to the main frame. The drive comprises a motor, which drives a drive element, which moves the pallets. A processing device is provided on the main frame to process sheet-like material positioned on the pallets in the main frame.

Abstract: A machine tool has a cover that prevents chips generated by machining and cutting fluid from scattering around and a plurality of movable nozzles with liquid discharge directions thereof being movable so as to wash out chips that have adhered to or accumulated on an inner surface of the cover. The machine tool is capable of changing a discharge direction of each of the movable nozzles individually. The machine tool compares the state of the inside of the cover before start of machining with the state of the inside of the cover after chips are generated to determine an adhesion or accumulation state of chips. The machine tool thus calculates the liquid discharge direction to wash out chips from the movable nozzles based on a result of the determination.

Abstract: A machine tool that machines a workpiece by a tool includes a workpiece spindle device that holds the workpiece in a rotatable manner with a predefined workpiece rotational axis Rw as a center, one or more in-machine robots, and a connecting mechanism that attaches the one or more robots on the machine tool so that the one or more robots move independently from the workpiece, with the workpiece rotational axis Rw serving as a center.

Abstract: A method produces a component, particularly a body component for a vehicle, or a component composite consisting of several components. The steps include forming a metal plate in a forming tool, particularly in a deep-drawing die, producing a reference marking at a predefined location of the metal plate, rough positioning of the formed metal plate by a positioning device such that the reference marking is situated in a predefined space area, identifying the reference marking of a position recognition device, such as a camera system, the position recognition device generating position data corresponding to the position of the reference marking, positioning of a first fixing element at the location of the reference marking based on the position data by an electronically controlled positioning device, and connecting the first fixing element with the formed metal plate, particularly by welding.

Abstract: Device and method for the finishing machining of an internal face of a workpiece, such as the track of a ball screw, including a workpiece holder and a finishing tool held on a finishing tool holder. A rotary drive is provided, by which the workpiece holder and the finishing tool is rotationally driven relative to one another about a rotational axis. A linear drive is provided, by which the finishing tool held on the finishing tool holder and the workpiece holder is driven in a translatory manner relative to one another along the rotational axis. An oscillating drive is provided, by which the finishing tool held on the finishing tool holder and the workpiece holder is driven in an oscillating manner relative to one another in the direction parallel to the rotational axis and wherein the finishing tool is pivotably held on the finishing tool holder about a pivot axis.

Abstract: An apparatus for treating a floor surface includes a floor grinder-polisher system including a support frame and a plurality of grinding heads mounted on the support frame, a power source connected to the plurality of grinding heads and configured to supply power to the plurality of grinding heads, a controller configured to control the plurality of grinding heads, and a vehicle connected to the support frame and configured to support the power source. Each grinding head includes a grinding surface configured to rotate and engage a floor surface.

Abstract: An ophthalmic lens processing apparatus is provided that includes a housing, a support structure, and ophthalmic lens processing components configured to perform an ophthalmic process on an ophthalmic lens. The housing includes a case and a user access member. The support structure includes a support plate received within and movably connected to the case. At least one of the ophthalmic lens processing components is mounted to and movable with the support plate. Also provided is a method of improving user accessibility to the at least one ophthalmic lens processing components of the ophthalmic lens processing apparatus.

Abstract: A polishing method is used for polishing a substrate such as a semiconductor wafer to a flat mirror finish. A method of polishing a substrate by a polishing apparatus includes a polishing table (100) having a polishing surface, a top ring (1) for holding a substrate and pressing the substrate against the polishing surface, and a vertically movable mechanism (24) for moving the top ring (1) in a vertical direction. The top ring (1) is moved to a first height before the substrate is pressed against the polishing surface, and then the top ring (1) is moved to a second height after the substrate is pressed against the polishing surface.

Abstract: PROBLEM: To provide a finishing method for a painted surface that can reduce the number of processing steps, and that can shorten the finish polishing time and reduce the polishing area. RESOLUTION MEANS: The painted surface finishing method of an embodiment of the present disclosure includes a step of removing irregularities in a painted surface using a polishing material including a polishing layer with a structural surface where a plurality of three-dimensional elements are arranged, and providing a surface suitable for finish polishing; and a step of finish polishing the surface; wherein the polishing layer contains abrasive diamond particles with an average particle diameter of 0.5 to 5 ?m, and a binder containing an epoxy resin.

Abstract: An apparatus for controlling a movement of a grinding wheel of a semiconductor wafer grinding system includes: an interface to obtain a feedback signal including grinding force information indicating a force applied to a semiconductor wafer by the grinding wheel; and a control module to generate a control signal for controlling the movement of the grinding wheel based on the grinding force information. The control module generates the control signal to trigger a forward movement of the grinding wheel according to a desired velocity profile during the grinding, if the grinding force information indicates that a force applied by the grinding wheel is below a force threshold. The control module generates the control signal to trigger a movement of the grinding wheel slower than the desired velocity profile during the grinding, if the grinding force information indicates that the force applied by the grinding wheel is above the force threshold.

Abstract: A method for raising a polishing pad for polishing a silicon wafer, wherein a polishing pad made of foamed urethane resin is attached to a polishing machine, after dressing is performed, dummy polishing is performed, after processing to remove the polishing residues that have built up in the polishing pad by the dummy polishing is then performed, an amount of polishing residues in the polishing pad is measured, and a rise of the polishing pad subjected to the dummy polishing is judged based on the measured amount of polishing residues. As a result, a method for raising a polishing pad can improve the particle level in the polishing pad life early stage.

Abstract: A power tool that drives rotary cutting element has a retractable guard for the cutting element, and a guard control apparatus allows a user to maintain the guard in a retracted position during operation of the power tool. The guard control apparatus includes an auxiliary handle fastened to the housing of the power tool, and latching elements linked to a spring-biased lever mounted in the auxiliary handle for selectively and temporarily retaining the retractable portion of the guard in a retracted position to enable plunge and other complex cutting operations. Maintaining the retractable portion of the guard in the retracted position during operation of the power tool thereby occupies both hands of the user. This not only helps the user stabilize and accurately control the power tool, but also keeps both of the user's hands safely away from the exposed cutting element in the event of a sudden kickback.

Abstract: Systems and method for tool path approximation may comprise approximating the outer surface of a part to be worked. The outer surface may be approximated by a plurality of airfoils. Moreover, the system and methods approximate a tool path based on a cutting tool and convert the tool path to accommodate a non-cutting processing tool. The tool path may be implemented on a computer numerically controlled machine that is configured to control a flexible fork peening tool.

Abstract: A superabrasive wheel having a superabrasive grain layer having superabrasive grains fixed by a binder, a ratio of an area occupied by the superabrasive grains in the superabrasive grain layer being 20% to 70%.

Abstract: A coated abrasive article includes a backing, a make layer, crushed abrasive particles, and a size layer. The crushed abrasive particles include: 35 to 100 weight percent of initial crushed abrasive particles having a first composition and first size grade, wherein a majority of the initial crushed abrasive particles are platey crushed abrasive particles, and wherein each platey crushed abrasive particle has a respective length, width, and thickness; and 0 to 65 weight percent of crushed filler particles having a second composition and a second size grade. The first and second compositions and/or size grades are different. The coated abrasive article has a direction of intended use, a majority of the platey crushed abrasive particles of the coated abrasive article are positioned with their thickness oriented substantially parallel to the direction of intended use. A method of making the coated abrasive article is also disclosed.

Abstract: An abrasive article and method of making same wherein the abrasive article comprises a mounting assembly and an abrasive attachment assembly wherein the first interlock member of the mounting assembly and the second interlock member of the abrasive attachment assembly are configured to align the central axis of the abrasive attachment assembly and the central axis of the mounting assembly, and the first interlock member releasably engages the second interlock member. The abrasive article is adapted to clean a work surface area around studs using a rotary tool, including, for example, a drills or die grinder.

Abstract: A superabrasive element includes a substrate and a superabrasive table bonded to the substrate, the superabrasive table including a polished surface having a polished finish, the polished surface extending over at least a central, apical region of the superabrasive table, and an unpolished surface including an unpolished finish, the unpolished surface surrounding a majority of the polished surface. A method of manufacturing a superabrasive element includes providing a superabrasive element having a substrate and a superabrasive table bonded to the substrate and polishing at least a central, apical region of the superabrasive table to form a polished surface, without polishing an unpolished surface of the superabrasive table, the unpolished surface surrounding a majority of the polished surface.

Abstract: A pipe clamp rotation kit preferably includes an adjustment end bracket, a pipe end bracket, an adjustment end collar, a pipe end collar and a tightening member. The adjustment end bracket includes a L-shaped bracket and a support pin. The support pin is sized to be received by an inner diameter of a support pipe of a pipe clamp. The pipe end bracket includes a pipe mounting plate and a pipe support plate. A pipe hole is formed through the pipe support plate to receive the support pipe of the pipe clamp. The adjustment end collar includes a collar base and a pair of ears. The support pipe is inserted through a bore in the collar base. A space between the pair of ears is sized to receive a lead screw of the pipe clamp. A threaded stud of the tightening member is threaded into the adjustment end collar.

Abstract: Disclosed herein is a clamping apparatus that includes an upper jaw structure having a hinge end and a clamp end, a lower jaw structure having a hinge end and a clamp end, and a hinge located at the hinge ends of the upper and lower jaw structures, the hinge providing for rotation of upper jaw structure with respect to the lower jaw structure. The clamping apparatus includes an elongated element threadably attached to the first and second upper jaw structures between the hinge end and the clamp end of each of the first and second upper jaw structures, wherein rotation of the elongated element in a first direction causes the clamp end of the upper jaw structure to move closer to the clamp end of the lower jaw structure. The elongated element includes an end configured to receive a tool configured to facilitate the rotation of the elongated element.

Abstract: Present invention teaches a magnetic pad to work with clamping tools where the magnet and protrusions on the top surface provide for easy aligning and connection from the clamping tool to the pad, relying primarily on the use of a ring-shaped magnet embedded in the top surface. The bottom surface provides flexible holding surface upon work pieces with two grooves of different sizes. The pad materials can be made from soft metals to eliminate marring the surface of work pieces.

Abstract: An elongated, generally, cylindrical impact socket has a driven end and a drive end. The socket is elongated, the cylindrical shape is parsed in at least two, distinct uniform diameter generally coaxial sections having a mass in the range of at least about 2 to 3 times the mass of a standard or extended ASMEB107.110.20R socket.

Abstract: A sleeve device includes a main unit having a sleeve with an open end face, a receiving space intercommunicating with the open end face, and a radial hole. An engaging member extends into the receiving space. A fixing member is mounted to an end of the receiving space opposite to the open end face. A pressing member is slideably received in the receiving space for pressing against the fixing member. The pressing member includes a cylindrical portion, an abutting portion, and a pressing portion, with the abutting portion and the pressing portion disposed on two ends of the cylindrical portion. A positioning member is slideably received in the radial hole for selectively pressing against an outer periphery of the cylindrical portion or the pressing portion. A ring is rotatably mounted around the sleeve and includes an inner periphery and a first recessed portion for selectively abutting the positioning member.

Abstract: A torque reactor employs a first socket with a first drive element engaging the first socket and a second socket with a second drive element engaging the second socket. The first drive element has a first receiving channel and the second drive element has a second receiving channel. A shaft is received in the first receiving channel second receiving channel. A first engagement mechanism secures the shaft in the first receiving channel and a second engagement mechanism secures the shaft in the second receiving channel.

Abstract: An oblique fastening apparatus includes first and second clamping units. The first clamping unit includes a first main body, a first guide member, a first clamping member, and a first oblique fastener passage extending through the first guide member and the first clamping member and having a first discharge section communicating with ambient atmosphere. The second clamping unit includes a second main body movable relative to the first main body, and a second clamping member. The first and second clamping members are configured to clamp a workpiece therebetween. A guide unit is provided to guide relative movement of the first and second main bodies.

Abstract: Torsion control device and method for an electric impact power tool are provided. The electric impact power tool includes a motor, and the torsion control device detects an actual rotational speed of the motor to make the electric impact power tool output a preset torsion value accurately. In the torsion control method, a compensating time is calculated according to a difference between the actual rotational speed value of the motor and a preset rotational speed value.