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This means that having two different kinds of parts "out" at the same time is a serious problem.
For smaller quantities you can use double sided tape and stick the component tape to the bench. I've done several stints as a surface mount solderer, mostly on prototype and small (under 20) production runs, for a company involved in research.
My supervisor used to go one step further and put one part down per board and then move on to the next board. I usually tin all the tabs on one side at once, take out the number of parts needed, place them down on the tinned pads one at a time, then move back to the first one with the solder and complete both the remaining connections, and fill up the original tinned pad.
While I certainly wouldn't suggest ever tipping the entire board's components into a single pile and having to work out which is which, after a while you do get a feel for the different parts; even two identical parts from different manufacturers will have a slightly different colour to them, or overall size may be slightly different. You didn't really specify if you are hand soldering, machine soldering, pick and placing with solder paste and an oven, etc. Not the answer you're looking for?Browse other questions tagged components surface-mount or ask your own question.
If someone is still not aware of what electricians can do, it is necessary to know that they are able to deal with all kinds of aspects related to maintaining, installing, and fixing different electrical systems and lighting. People should not forget that they may require some emergency lighting services quite unexpectedly. It is obvious that experienced and licensed professionals are willing to work on any project, regardless of its size. Another popular reason to hire those specialists is the installation of good quality communication cabling. Engine Room Tools, 1949, is a training manual that focuses on the correct use of tools aboard ship. The staff of the United States Maritime Service Institute wishes to acknowledge the valuable aid given by the following organizations in granting permission to use material from their publications.
Except for certain special tools that are taken up later in connection with the equipment on which they are used, these lessons describe the hand tools commonly worked with in the engineering department of a ship, and explain certain precautions that should be taken in using and caring for such tools. The information in the lessons is extremely important to all who desire to be completely familiar with and well trained in the knowledge and uses of hand tools. The Tools lessons will be found quite elementary in places, since they are prepared so as to be suitable for the beginning student, as just explained. Good tools are carefully made, and must be handled properly if they are to work and last as intended.
A good mechanic will take care of his tools, as valuable time and possibly lives may depend on the accomplishment of a piece of work quickly and accurately. When work is being done, the necessary tools should be kept within easy reach, but not where they can fall and be damaged, or where they may fall and injure someone, as might occur from an upper level in the engine room.
Tools should never be placed on the finished parts of a machine, on the ways of a lathe, for example. Some tools can be used for several purposes, but using the wrong tool may ruin not only it, but the work as well. The way in which tools are handled, and the care given to them, indicates the quality of workmanship and the kind of engineering to be expected in your department.
The ball-peen hammer, often termed the machinist's hammer, is a very useful tool aboard ship.
The straight-peen hammer is used for spreading or drawing out metal in line with the handle, while the cross-peen hammer is used for the same operation at right angles with the handle. When using a hammer, it should be held near the end of the handle with the face of the hammer parallel to the work.
Keep the hands and the hammer handle free from grease and oil, otherwise the hammer may slip from the grasp. The offset screwdriver makes work possible in tight corners where the straight type will not enter.
The Phillips-type screwdriver is made with a specially shaped blade to fit Phillips-type cross-slot screws.
Some screwdrivers have handles made of insulating material, and are useful when electrical work is being done. Side-cutting pliers are used principally for holding and bending thin material or for cutting wire.
Avoid using pliers on a hardened surface, as such use dulls the teeth and causes pliers to lose their gripping power. When cutting from the edge of a large sheet, it is advisable to cut from the left-hand side. When cutting large sheets of metal, it is helpful to lay the metal on the bench and make the cut with the lower handle of the snips resting on the bench top. A center punch is used to make a starting mark for a drill when holes are to be drilled in metal. After a pin or bolt has been loosened or partially driven out, it may be found that the starting punch is too large to finish the job. The alining, or lining up, punch is used to line up corresponding holes in adjacent parts, for example when working on engines that have pans and cover plates. When it is necessary to make gaskets of rubber, cork, leather, or composition materials, a gasket punch, one type of which is shown in Fig. Be sure to keep fingers clear of the jaws when clamping work in the vise, and use care to keep them from being pinched between the end of the handle and the head of the screw, the latter accident being a very common one. The size of an open-end wrench is usually stamped on the face, and denotes the width of the opening between the jaws of the wrench.
The jaws of open-end wrenches are placed at an angle in order to make it easier to work with the wrenches in close quarters, as it is frequently necessary to tighten or loosen a nut where there is very little space in which to swing a wrench. There are special open-end wrenches, such as tappet wrenches, which are very thin and have extra long handles.
When it is necessary to exert considerable force on a wrench, it is usually advisable to pull instead of push. Some wrenches are designed for a particular job, to tighten the nuts on the handhole and manhole plates of a boiler, for example. There is little chance for a box-end wrench to slip off the nut, and it cannot spread on the nut and cause undue wear. When using box-end wrenches, and there is insufficient room to turn the wrench in a complete circle, it is necessary to lift it off the nut after each pull and then place it back on in another position.
To use a detachable socket wrench, select a socket that fits the nut, place the socket on the projecting lug of the handle and then place the socket over the nut. The ratchet handle permits the wrench to be turned without removing it from the nut, a gear shift often being incorporated in the construction so that the nut can be turned in either direction without turning the wrench over. The accuracy of a torque wrench reading depends in part upon the condition of the threads of the bolt or nut and on the lubrication of the threads.
Hacksaw blades have holes in both ends and are mounted on the frame by means of pins attached to the frame. Blades are made of high-grade tool steel or tungsten steel, and are available from 6 to 16 inches in length. When selecting a blade, it is also necessary to consider the set, which means that some teeth are pushed sideways in one direction and the same number in the opposite direction, according to definite patterns. It is often helpful to file a V-shaped nick at the starting point; the blade will then start more easily.
When a saw blade is broken and a new blade is to be used, turn the work so that the cut can be resumed on the other side, if possible.
The diamond-point chisel is tapered square at the cutting end, then ground at an angle to provide the sharp diamond point.
Double-cut files have criss-crossed rows of teeth, the double cut forming teeth that are diamond-shaped and suitable for quick removal of metal and for rough work. Mill files are tapered both in width and thickness, and are available with either square or round edges, or with one safe edge, that is, an edge with no teeth.
Flat files are general purpose files, tapering in width and thickness, and generally used when a fast cutting tool is desired. Square files are tapered on all four sides and are used to enlarge rectangular-shaped holes and slots. The half-round file is a general purpose tool, the rounded side being used on curved surfaces and the flat face on flat surfaces.
File handles are made of wood with a ferrule, or metal strengthening ring, on the end, and a hole to receive the tang of the file. During the operation of filing, small particles of the work are likely to clog the teeth of the file and scratch the material being filed.
To prevent scratching or cutting too deep when filing wrought iron, steel, or hard fiber, apply a little oil to the surface of the file. However, do not use oil when filing cast iron, as it causes the cast iron surface to glaze over and become hard and slick.
Twist drills are also used for cutting larger holes in metal, up to 4 inches in diameter, but for such purposes are usually operated by power drilling equipment.
The drill shank is the end that fits into the chuck of the hand drill, electric drill or drill press.
Twist drills are available with either 2, 3, or 4 flutes (the spiral grooves formed along the sides), but drills having 3 or 4 flutes are used for following smaller drills or for enlarging cored holes, and are not suitable for drilling into solid stock.
Tables of drill sizes will be found in Marine Engineering Tables, issued later in the course.
If the size number has worn off the drill shank, the size can be checked with a drill gage, Fig. The lip clearance angle is the angle at which the drill point is ground off just back of the lips. The margin is the narrow strip which extends the whole length of the flutes, being part of a cylinder that is interrupted by the flutes and by what is known as body clearance. The portion of the drill back of the margin is of slightly less diameter than the margin, and the difference is known as body clearance.
It runs the entire length of the drill between the flutes, gradually increasing in thickness toward the shank. Next take a drill that needs grinding badly, and start up the grinder and try to shape the point of the old drill to be exactly like the correctly ground drill. With the addition of a special attachment which converts the rotary motion of the drill into a reciprocating motion, a portable power drill can be used for making holes in concrete and similar materials. Except for the smallest units, the extension cable of portable electric drills should include a ground lead from the drill casing, and a clip for connection of the ground lead to ground. Portable electric drills are susceptible to short circuits because of their small clearances and the metallic dust produced when they are used. Before a portable power drill is used, the extension cable should be inspected carefully to -make sure that it is not frayed or crimped to such an extent that wiring is exposed. One advantage of the drill press over the portable electric drill is that speed control is provided. The feed pressure is easily controlled on this drill press by means of a feed wheel with long handles.
It is usually advisable to protect the drill table by placing a block of wood beneath the work, thus preventing the drill from touching and scarring the drill table as it completes the drilling of a hole.
As shown in the illustration, the base of the device is bolted or clamped in position, and the adjustable arm is placed at the proper height so that the pointed tip of the ratchet fits into one of the countersunk holes in the lower face of the arm. Soft solder is used most often in sheet metal and electrical work, and is usually a combination of 50 per cent tin and 50 per cent lead, known as half-and-half solder.
The points of soldering irons should be rather blunt for efficient heat conduction, three different shapes being shown in Fig. How might one keep small (<100) quantities of such parts properly organized during assembly? I typically have a few "trays" of them, where one is for capacitors, one is for resistors, etc. Mike from mikeselectricstuff Youtube channel has a nice video showing this technique: Some random hints for quick hand SMD assembly.
One of the jobs called for 40 sot-23 diodes per board (20 boards in the job) I found it was easier to leave them on the ribbon, and just pull out 10 at a time.
It worked for him but I found it wasted a lot of time jumping between boards, especially if multiple parts were placed right next to each other.
You tend to get a feel after a while if the part you have picked up is the right one, particularly when using the single ribbon method; the eye can pick out one different part fairly easy. It makes sense to get a better understanding of the most common services that they provide to be aware of how to choose the best one.
This means that they risk ending up making one common mistake, as they choose the first electrician they see. It is connected with the maintenance, installation, and design of specific fire detection systems. PPlease report any typos, or particularly annoying layout issues with the Mail Feedback Form for correction. In order that the coverage will be as complete and helpful as possible, the lessons also include a description of some tools that might not be found aboard ship, but that would be encountered in shipyards, machine shops, and other places where maintenance and repair work is done. It will aid the beginner, for example, to identify and locate the right tool for a job and help him to perform his work more efficiently. They should be studied carefully, however, as this will enable all students to practice the art of study (which they may not have been doing recently) and will help them to master the more difficult engineering principles that follow in later lessons. Good tools are essential if a mechanic is to do his best work quickly, properly and accurately. He will keep cutting tools sharp, grind them, if necessary, when through using them, and store them so that their edges will not be damaged or dulled by contact with each other or with other hard objects. It is advisable to spread canvas along a grating, if tools are to be placed on it, or if work is being carried on where tools might drop and fall through it.
Sharp tools should not be carried in the pockets of clothing or left protruding from work benches, as they may tear or puncture objects with which they come in contact, including the workman. Hammers.-The hammer is a very simple striking tool, being just a weighted head and a handle to direct its course. It should also be remembered that oil or grease on the hammer face may cause it to slip off the work and lead to a painful bruise.
The blade must have sharp corners and fit the slot in the screw closely; otherwise it is likely to slip and damage the slot. It has one blade forged in line with the shank, and the other blade at right angles to the shank.
When a screwdriver with an insulated handle is not available, the handles of other screwdrivers can be insulated by wrapping them with tape. 4 has a round shank, some heavy-duty screwdrivers are made with a square shank, the construction enabling the torque of the screwdriver to be increased by applying a wrench to the square shank. Do not use pliers for loosening or tightening nuts, as the flats of the nuts will become damaged. They are also handy for cutting the soft wire which is passed through small holes in nuts and bolt heads to "safety" them, or prevent them from working loose. Shears and Snips.-Hand shears, or snips, are used for cutting sheet metal of various kinds and thicknesses. The blades are small enough to permit sharp turns, and will also cut outside and inside curves.
Snips do not remove any of the metal when making a cut, but work with a shearing action that tends to roughen the edges of the material. This allows the small piece being removed to curl out of the way of the snip blades as the cut is made. To do so, the blades should be taken apart and the cutting edges ground to an included angle of 85°.

This lessens the strain on the worker's hand and allows him to use his weight to advantage. If the center punch mark is not made, the drill will wander or "walk away" from the desired center.
A pin punch can then be used, as it is designed to follow through the hole without jamming.
Soft jaws, which are inserts of brass, copper, or other soft metal, can be made from scrap metal and mounted on the jaws of a vise when the surface of the work must be protected. When holding heavy work in a vise, it is advisable to place a block of wood or metal under the work as a prop to prevent it from sliding down and perhaps falling to the floor or on the foot. If it is necessary to pound against metal parts held in a vise, be sure to pound against the back jaw, as it is heavier than the front jaw and strong enough to absorb the shock of the blows. Clamps.-When a vise is not available, a clamp can be used to hold pieces of material together while they are being worked on. Wrenches.-Fundamentally, the wrench is a tool for exerting a twisting strain, as in turning bolts and nuts. Although not shown in the illustration, the wrench will have to be turned over at the end of each swing. They are used to adjust the valves of small internal combustion engines, and must be handled with care.
Some wrenches are so large that a pulling strain is taken with a chain fall, and the wrench is then struck by a heavy ram supported by a block and tackle and wielded by several men. Pushing on a wrench may be dangerous, as a sudden loosening of the nut can lead to striking some part of the body against the machine being worked on. Since the leverage of such a wrench is proportioned to the strength of the studs and other material being tightened, use the correct wrench, and do not add to its leverage by slipping a piece of pipe over the end. Adjustable Wrenches.-A handy all-round wrench for light work is the adjustable open-end wrench, such as shown in Fig. An adjustable wrench will not stand the hard usage of an open-end wrench and must be used very carefully.
20, are useful in many instances, when tightening or loosening pipe unions, for example, or where the exact size of open-end wrench is not available. Because the sides of the box opening are comparatively thin, the wrench is suitable for turning nuts that are hard to reach with an open-end wrench. The socket is held on the lug by a small friction catch that engages when the socket and lug are forced together.
This is very important in many cases, enabling a workman to tighten the bolts of a crankpin bearing, for example, to the exact tension specified by the manufacturer of the engine, and to make sure that cylinder-head nuts are all evenly tightened according to instructions.
The Bristo-type wrench has a number of splines on the shaft, the design tending to reduce spreading. Hacksaws.-The hacksaw is a tool used to saw metal, and consists of a handle, frame and blade.
The blade must always be mounted in the frame with the teeth pointing away from the handle, and should be tightened with enough tension to hold it rigidly between the pins. When selecting the best blade for a job, it is necessary to consider the type of blade and the pitch. The set provides clearance for the blade so that it will not jam and stick, and also prevents overheating the blade. When preparing to use a hacksaw, secure the material in a vise, or with clamps, if it is not already firmly anchored. Hold the saw at an angle that will keep at least 2 teeth cutting all the time, otherwise the blade will jump and individual teeth will be broken.
The reason is that the set of the new blade is greater than that of the used saw, and the new blade would possibly jam if work were continued at the same place. They are also used to shear off rivets, to smooth castings, to split rusted nuts from bolts, etc. Do not look at the head of the chisel while striking it with the hammer; watch the cutting edge. The last few strokes, however, should be made lightly in order to avoid unnecessary damage to the supporting surface. Chipping is the term applied to the method of removing metal from a surface with a chisel, as shown in Fig. Special Cold Chisels.-If it is necessary to cut keyways or slots, the cape chisel can be used. This chisel is also used to "draw back" a drill that has "walked away" from its intended center. In selecting a file for a job, it is necessary to consider its shape, which means both the outline and the cross-sectional shape. Files are also graded according to the spacing and size of their teeth, or their coarseness and fineness. If the teeth of a 6-inch, single-cut smooth file, for example, are compared with those of a 12-inch, single-cut smooth file, the difference will be noted.
The type of material to be filed, and whether it is a rough or finishing cut, determine the grade of fineness that is required. The usual way of driving the handle on the file is to insert the end of the tang into the hole in the handle, and then tap the end of the handle on the bench or some other flat surface. Unless the file is lifted from the work on the return stroke, it will become dull much sooner than it should.
If a few chips are stubborn and will not come out, remove them with the pick that is included with the file card.
A file is easily dulled by rough or improper handling, and files therefore should not be stored in a drawer or box where they can rub against each other or against other tools. Drills and Drilling.-There are many occasions when it is necessary to drill holes in metal, using a twist drill, a tool that does its work by slicing metal away as it rotates.
Carbon steel drills are satisfactory for the general run of work and are less expensive, although they may lose their hardness if heated excessively.
53, for the number drills, with a drill stand for fractional drills, or with a micrometer for any kind of drill.
Use of Lubricant.-When drilling, some materials require no lubricant while others require a lubricant peculiar to their nature.
Drill Terminology.-Before a drill is used on any kind of work, it is important that it be correctly ground and sharpened. It is formed by the intersection of the cone-shaped surfaces of the point and should always be in the exact center of the axis of the drill.
Body clearance reduces the friction between the drill mid the walls of the hole, while the margin insures that the hole is of the right size. Rake Angle.-The rake angle of a drill is the angle of the flutes in relation to the work, as shown in Fig. Grinding a Drill.-After the instructions have been studied carefully, considerable practice is still needed in order to learn how to grind a drill correctly. Remove very little metal at first and examine the drill frequently in order to note the progress made.
Make a light mark with a prick punch where the lines intersect, and check to make sure that the prick punch mark is located exactly where they cross.
Portable Power Drills.-A portable electric drill is used in much the same way as a hand drill. Small drills are geared up for high speed, but the larger drills are geared down so that the chuck will turn slowly enough to prevent damage to the drill from burning.
The clip should be fastened to a grounded conductor, such as the conduit at the outlet box, before the drill is placed in operation.
These conditions can be improved by periodically blowing through the motors with clean dry air. A depth stop is provided to stop the progress of a drill at a predetermined depth, which is important when drilling holes that do not go all of the way through the material.
Never try to hold it down by means of the hands, as the drill may catch or jam and spin the material around at high speed, endangering everyone within range. Heavy-duty Ratchet Drill.-When the hole to be drilled is too large for an electric drill, and the piece to be drilled cannot be taken to a drill press, a heavy-duty ratchet drill can be used. The arrangement may utilize blocking, depending upon the nature and position of the work, or a device known as an "old man" may be used. The position of the arm is then adjusted so that the drill is lined up properly, and the arm is bolted securely on the upright. Pilot Holes.-A small hole, used to guide and mark the path for a larger drill, is known as a pilot hole.
Countersinks.-A countersink is used to shape the ends of drilled holes to fit screw, bolt, and rivet heads of the countersunk type.
The pilot end of the tool is smooth, and is guided by the hole drilled for the bolt or screw. Solder.-Solder is used to join pieces of metal, to make metal joints and seams leakproof, and to connect electric wires so that they will be good conductors. Solder is manufactured in both bar and wire forms, some wire solders having hollow centers which are filled with acid or rosin core fluxes. It does not have much strength, and should never be used where heavy stresses will be applied to the soldered parts.
They will withstand considerable stress, pressure and vibration, and may be used to solder high-pressure pipe connections, gasoline and oil piping joints, etc. Blowtorch.-Soldering irons can be heated in various ways, but the gasoline blowtorch is one of the most convenient means aboard ship. Complete all the parts of one type on one board and then move onto the next board, then jump back to the first board for the next part. This is when they need to hire qualified specialists who will check the efficiency of the existing ones.
It is interesting and certified electricians are also able to advise the best type of cabling in accordance with the basic needs and requirements of their clients. It should also contain much of interest to engineering personnel who have picked up their knowledge of tools more or less by chance as their work required various tools to be used. This is especially important aboard ship where it may be .impossible to procure a replacement when needed.
Some tools should be kept close by the machine for which they are designed and on which they are used.
It is also possible to check more readily to see whether any tools are missing, and, if so, which ones they are. He will handle delicate measuring instruments with care, and will not keep them where they might be damaged by heavy tools. Openings in the engine or other equipment being worked on should be covered or plugged to prevent tools, nuts, bolts, etc., from accidentally falling through the openings.
If a chisel is used instead of a wrench, an important part of the machinery may be scarred or broken.
They can be procured in both single-face and double-face types, a double-face sledge being shown in Fig. It is also important that a screwdriver be held firmly against the screw to prevent it from slipping and injuring the worker or the work.
This checks the tendency of the screwdriver to slide out of the slot onto the finished surface of the work. If the end of the blade is damaged, it can be made serviceable again by means of a grinding wheel.
It is also bad practice to try to turn a screwdriver with a pair of pliers or to use it as a chisel.
The various lengths and shapes of flat-nose, round-nose, and needle-nose or long-nose pliers make it possible to bend or form metal into a variety of shapes, to hold objects in tight spots, and to make delicate adjustments.
When diagonal-cutting pliers are used, the cut should be made with the throat of the jaws, not with the points, as the latter use would increase the tendency to spring the jaws apart. They must not be overstrained, however, as their thin cutting edges are easily nicked and dented. It is difficult, however, to cut circles and arcs of small radii with straight snips, the scroll-pivoter snips being more suitable for such purposes. Blade tension is adjusted by turning the nut on the pivot bolt, or pin, holding the blades just tight enough to remain in any position in which they are placed.
They may be used for knocking out rivets after their heads have been cut off, or for freeing pins or bolts from their holes.
It is heavy enough to resist damage to itself, but soft enough not to injure the finished surfaces of the parts being removed. The screw that operates the movable jaw should be lubricated frequently with light grease or heavy cylinder oil.
As the majority of nuts and bolt heads are hexagonal, or 6-sided, many wrenches are specially designed to fit hex-heads and hex-nuts. If the wrench opening is too large, the wrench will slip around the nut and round off the corners of the hex-faces, possibly springing the jaws of the wrench at the same time. Whenever considerable effort is to be applied to a wrench, make sure that the footing is secure and take precautions against stumbling, slipping and falling. Exceeding the designed leverage in this manner can cause stripped threads and broken studs, nuts and other parts, and lead to the breakdown of a piece of machinery and injury to personnel. It is important that its jaws be closely adjusted to fit the nut, and it should always be used so that the force of the pull comes on the solid, or stationary, jaw, as shown in Fig.
22, is therefore helpful, using the box end for starting the nuts when loosening them, or for final tightening, and the open end for faster turning. Pin spanners have a pin instead of a lug, the pin fitting a round hole in the edge of the nut.
An all-hard blade is best for sawing brass, tool steel, cast iron, and heavy cross-section stock. Since the blade has a thickness of about .025 inch, the set causes it to make a cut about twice that wide.
After the first few strokes, make each one as long as the hacksaw frame will allow, thus preventing the middle teeth from overheating and wearing rapidly. If hacksaw blades are worked too fast, the heat that is generated may draw the temper and make the- blade soft and useless. If it is necessary to use the new blade exactly in the same cut, however, run it through the unfinished part very carefully before attempting to complete the job.
36, which also illustrates the correct and incorrect methods of preparing the cutting edges. In some cases, pieces of the jagged edge may break away and fly off with sufficient force to injure someone working nearby. The safest method is to have a guard (a piece of canvas of sufficient size attached to two wooden pedestals) placed so as to catch the flying chips. They vary in length, in shape, and in arrangement, or cut, of teeth, so as to provide files for various uses. These grades are known as rough-cut, middle-cut, bastard, second-cut, smooth and dead-smooth. If a file is used without the handle and it strikes something accidentally or jams to a sudden stop, the tang may be driven into the hand.
If the tang of the file is considerably larger than the hole in the handle, the hole may be enlarged by burning it out with the heated tang of a file. Most of the damage to new files is caused by using too much pressure during the first few strokes, so it is necessary to use a light pressure to prevent tooth breakage.
Pinning is sometimes the result of putting too much pressure on the file, especially if it is a new one. The shank diameter of a straight-shank drill is usually a few ten-thousandths of an inch smaller than the point diameter.
If a drill is not in proper condition for work, it will drill with difficulty, make a hole that is rough or off size, and perhaps break while in use.

When the cutting edges are not the same length, the hole will be larger than the drill, as shown in the center view.
60, use a round-nose chisel to make a nick in the impression on the side of the center toward which the drill should be drawn.
If the drill catches while finishing the hole, work the drill back and forth carefully until it cuts through the work.
Portable power drills can also be used for such operations as buffing, polishing, and grinding. This precaution protects the operator of the drill from electrical shock in case the insulation of the wiring within the power drill casing should fail, resulting in a short circuit. Since dampness is another reason that may cause the machines to deteriorate, they should always be stored in a dry place when not in actual use.
The operator of the drill should wear leather gloves and keep his footgear dry, especially where dampness may be present. The drill press in the illustration is arranged for high speed, with the belt on the largest step of the motor pulley. By turning the ratchet sleeve so as to screw it upward, the drill is held securely between the arm and the work, and drilling can be begun. The 3-flute 82° countersink is usually used, although other point angles are available for special purposes.
Solders containing 55 per cent to 70 per cent tin are stronger and can withstand heavier stresses than half-and-half solder, but no soft solder approaches the strength of the hard solders.
The hard solders must be melted with a blowtorch or welding torch; soldering irons do not conduct enough heat to melt them.
For example, consumers can decide to use the services of reputable Brothers Lighting employees. This is how it is possible to ensure that electrical systems will function properly for a long period of time. The correct procedure is to study Part 1, and complete and send in the examination for that part.
Even engineers with long experience may gain valuable information that they had not known about previously. Such objects within the cylinder or crankcase of an engine, and not observed and removed before starting up, can cause considerable damage. The flat portion of the head is called the face, and the other end is known as the peen, the latter being used for heading rivets and similar peening or drawing operations.
If such precautions are impossible, take care to have no part of your body in front of the screwdriver blade.
Needle-nose pliers are helpful when recovering a washer or nut from a place where it is hard to reach.
The blades of the latter tool are approximately at right angles and provide clearance for following curves.
Their narrow curved blades are beveled enough to permit sharp turns without buckling the material. If the points of the snips are allowed to come together, they will tear the metal as the cut is completed. Oil the pivot, spread a thin film of light oil on the blades to prevent rust, and keep the snip blades closed when they are not in use. 11 has set screws which enable the relative positions of the blades to be adjusted, if they should fail to meet properly after having been sharpened. These tools may be used for a variety of jobs, but the correct punch for the job should always be selected. Never use a center punch to remove a bolt or pin, as the sharp point will act as a wedge and tend to tighten the bolt or pin in the hole.
To start a bolt or pin that is extremely tight, use a starting punch that has a point diameter only slightly smaller than the diameter of the object that is being removed. The machinist's vise is a heavy-duty holding tool with parallel jaws and either a fixed or swivel base. Open-end wrenches with small openings are usually shorter than wrenches with large openings, thus proportioning the lever advantage of the wrench to the size of the work and helping to prevent breakage of the wrench or damage to the bolt or stud. These are heavy-duty wrenches, made with 4 inside faces for square nuts or with 6 inside faces for hex-nuts. This tool is used as a socket wrench handle in order to exert the desired amount of strain when tightening nuts and bolts.
In the case of a crankpin bolt, for example, with the engine in operation, such breakage would probably cause serious damage.
The hook spanner works on a round nut which has a series of notches cut in its outer surface. U-shaped spanners have either lugs or pins that fit in notches or holes in the top of the nut or screw plug. The pitch of a blade indicates the number of teeth it has per inch, pitches of 14, 18, 24 and 32 being available. A flexible blade is usually best for sawing hollow shapes and metals having a light cross section. Make sure that the hacksaw blade is the correct one for the purpose and that it is in good condition. Use just enough pressure on the forward stroke to make each tooth remove a small amount of metal.
Working too fast also may break some of the teeth, cramp and break the blade, or produce ragged and crooked cuts. However, if a dry wheel is used, the chisel should not be pressed too hard against the wheel, or held there for too long a time.
In some cases it is better to place the metal between two pieces of angle iron and clamp the whole set-up in the vise. The head of the chisel must therefore be periodically ground back to its original shape, as shown in B, Fig.
Keep the hammer and the head end of the chisel clean and free of grease and oil to prevent the hammer from slipping. A rasp is similar to the file except that it has coarse teeth raised by a triangular punch, and is usually used on wood. A piece of wet rag or waste should be wrapped about the file up to the tang before the file is heated, to prevent its temper from being drawn.
When filing, lean the body forward during part of the forward stroke and straighten up at the finish. For finishing work, a mill file gives better results, as it is a single-cut file and has a shearing action. A new file should not be broken in on a narrow surface, such as the edge of sheet metal, because the narrow edge is likely to break off the sharp points of the teeth.
They will keep on cutting when red hot, but should be cooled in still air; if cooled quickly they may crack or split.
It is important, therefore, to become familiar with the various parts of the drill, as identified in Fig. Take the drill to the grinder, and without turning on the grinder, observe just how the drill must be held in order to secure the correct shape of the point and the desired angles.
Select a sharp, properly ground drill of the desired size; insert the shank in the chuck and fasten it tightly in position.
When the hole is completed, withdraw the drill immediately by pulling it back as it continues to turn.
This drill press has a separate motor which drives the drill spindle and chuck by means of a V-belt. Remember that both too much pressure and too little pressure can cause overheating of the drill. Countersinks are made in a number of sizes, but any one size can be used on several different sizes of hole. An electric soldering iron, with interchangeable tips, can be used for light work and is especially good for work on electrical connections. They need to know that one of the most widespread options provided by those experts is related to the maintenance and installation of basic lighting systems. Besides, this is how property owners will cut their costs connected with emergency electrical repairs, as these can be avoided with ease. People should know that regular checkups are quite important for the safety of their family. It is possible to use all kinds of available informational resources to be able to succeed in their searches. Tools should be cleaned after being used, should be oiled, in some cases, to prevent rust, and should then be returned to their respective places.
This type has replaceable blades, a strong joint, and a short fulcrum that provides plenty of leverage. It should be noted, however, that both the circular and hawksbill snips must be used carefully, as their blades are easily sprung out of contact. There is no set rule for the amount to be allowed for dressing, but the thinner and softer the metal; the closer the cut can be made to the layout line. To use the gasket punch, place the gasket material on a piece of wood that has been cut across the grain, so that the cutting edge of the punch will not become broken or dulled.
It should be used only for holding material when hacksawing, filing, drilling, tapping, reaming, etc. A different kind of clamp is often used to make a temporary fastening in the engine room when it is desired to lift or take a strain on some object.
If cylinder-head nuts are tightened unevenly, stresses may be set up that lead to cracking of castings, stripping of threads, etc.
The dial-wrench is a special wrench for removing and replacing the dials of electrical and computing equipment.
The straight-handled hacksaw shown in the illustration is not adjustable, although it may be constructed with the adjustable feature.
A 14-pitch blade should be used on machine steel, cold-rolled steel, or structural steel, as it will cut fast and free. As the teeth point forward and the forward edges do the cutting, it is not necessary to use pressure on the back stroke. When near the end of the cut, slow down still more, so that the saw can be controlled when the stock is sawed through. This causes the center portion to receive the greatest shock, and protects the weaker corners. Too much pressure or lengthy periods of grinding will generate sufficient heat to draw the temper out of the steel. Hold the chisel in the hand with the head of the chisel close to the thumb and first finger, and grasp it firmly, but with the fingers rather relaxed. Single-cut files have rows of teeth cut parallel to each other, the teeth being set at an angle of about 65° with the centerline. Keep the hands as close together as possible to prevent bending the file, and watch the ends and corners of the work, as they are easily rounded. Too much filing of a piece of work in a lathe, however, will, as a rule, spoil it by making it out of round. A new file should never be used to remove the scale on cast iron; always use old, worn files for removing such scale. The tang is soft and bends easily, the body is hard and extremely brittle, and even a slight bend may cause a file to snap in two. If the rake angle is too small, it makes the cutting edge so thin that it may break under the strain of the work.
By working and observing carefully it will soon become apparent how the drill must be held in order to secure the desired results. In order to feed the drill into the work, a rod is placed in one of the small holes at the upper end of the ratchet sleeve, and by means of this leverage the ratchet sleeve can be held from turning during part of the stroke of the ratchet handle, thus lengthening the drill assembly and feeding the drill through the work.
If the wedge comes out and is lost, it must be replaced before continuing to use the hammer.
They are not of heavy construction, however, and should not be forced beyond their capacity.
Cutting in this way, especially with heavy metal, is easier on the snips and is not so likely to spring the blades.
Then hold the punch against the gasket and strike it with a hammer, driving the punch through the gasket where holes are required. Always tighten and loosen a vise by holding the handle with the hands, applying the weight of the body to secure the turning pressure.
It is also usually possible to position a hacksaw blade in any one of four positions, so that the operator can saw downward, upward, or to the right or left, as desired. The 18-pitch blade, which is the blade for general purpose work, is used on solid stock of aluminum, bearing metal, tool steel, high-speed steel, cast iron, etc. When finished with the saw, clean the chips from the blade, loosen the tension, and return the hacksaw to its proper place. A container of water should be kept at the grinder and the chisel dipped in it after each light cut. When chipping cast iron, chip from the edges of the work toward the center to avoid breaking off corners. Not more than 30 or 40 strokes per minute should be taken; too much speed will cause the file to rock, and the corners of the stock will be rounded off, as indicated in view A of Fig.
For a smoother surface than can be obtained by draw-filing, wrap a piece of fine emery cloth around the file and proceed as in draw-filing.
Bending or pounding a file, therefore, will not only injure the file but may cause steel particles to be thrown into the eyes. The rake angle also partly governs the tightness with which the chips curl, and hence the amount of space they occupy. Check the lip angle and lip clearance angle, and when the drill appears to be ground properly, try drilling a hole in a piece of soft steel scrap.
The amount of feed given is determined by the nature of the work being done, and can be judged by the amount of pull needed to move the ratchet handle.
They vary in size from 4 ounces to 2 pounds, three popular sizes being the 6-ounce for light work, the 12-ounce for general utility, and the 16-ounce for heavy work. A 24-pitch blade is used for cutting thick-wall tubing, pipe, brass, copper, and channel and angle iron. For similar reasons a small rat-tail file should not be salvaged to be used as a prick punch or center punch. Care should also be taken to see that snips are not used to cut wire, bolts, rivets, or nails, as such use will dent or nick the cutting edges. When the vise is not in use, the jaws should be brought lightly together, with the handle in the vertical position. It should not be kept in a drawer with other tools or where metallic objects will strike the blade teeth. Place the point of the drill in the center punch impression and begin drilling, making sure to keep the drill at right angles to the surface of the work. Examine the heel of the drill; if there are shiny spots, it is indicated that the lip clearance angle is too small. Be careful to keep both lips the same length, and have the included angle as previously recommended.

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Comments to «Different kinds of electrical tools and their uses»

  1. NIGHT_HUNTER writes:
    Workers who carry out more advanced every.
  2. Vefasiz_Oldun writes:
    Stroke and the space required, and similarly.

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