Successful operation filing depends on right choice the position of the body, legs and arms of the worker, as well as the uniformity of pressure and movement of the file.
When filing, the part is usually clamped in a vise mounted on locksmith workbench. If you have to clamp products with clean surfaces in a vice, then in order to avoid leaving dents on them from the notch of the sponges, they use lip protectors - soft metal squares superimposed on steel sponges. Hand grips are used for clamping small workpieces.
The reduction of fatigue and, consequently, the increase in labor productivity depends on the development of the correct skills in working with a file.
Hand position (file grip) is extremely important. The locksmith takes in his right hand a file with a handle attached so that its rounded end rests on the palm. Thumb the right hand is located at the top, along the handle of the file, and the remaining fingers cover the handle from below (Fig. 109, a). The file is placed on the workpiece in a horizontal position, and the left hand is located on the other end of the file (Fig. 109, b). The end of the handle should rest against the palm without much tension.
Rice. 109. Filing positions: a - right hand, b - left hand, c - body of the worker, d - legs
The position of the working body also has great importance to reduce fatigue and therefore increase productivity. The worker stands on the side of the vise at a distance of about 200-300 mm from the workbench.
The height of the vice should be such that when the hand with the file is placed on the vise jaws, a right angle (90 °) is formed between the elbow and shoulder parts of the hand. The correct position of the worker is shown in fig. 109, in. When filing thin layers When not much pressure is required, the body should be held straight by turning it at about a 45° angle to the vise. Concerning leg positions, then the left foot should be placed at the workbench, and the right foot should be moved back and to the right by about 200 mm. The angle between the midlines of the feet is usually 60-70° (Fig. 109, d). During the working stroke of the file (from itself), a large load will fall on the left leg, and during the reverse (idle) stroke, it will switch to the right leg, so that the muscles of the legs will alternately rest.
Of great importance when filing is balancing(Fig. 110, a), which consists in the correct increase in the pressure of the right hand on the file during the working stroke and the simultaneous decrease in the pressure of the left hand upon reaching a constant horizontal position of the file during operation. In the case of weakening the pressure of the right hand and strengthening the left, a forward blockage may occur (Fig. 110, b). With increased pressure of the right hand and weakening of the left hand, a blockage will turn back (Fig. 110, c).
Rice. 110. Sawing balancing:
a - the correct distribution of the pressure force, b - the force of the right hand, c - the force of the left hand
When filing, the teeth of the file leave traces on the work surface, called strokes.
The direction of movement of the file, and hence the position of the strokes, can be longitudinal, cross and circular. working longitudinal oblique stroke(Fig. 111, a) it is difficult to obtain a clean surface and achieve high productivity, therefore, to obtain a high-quality surface and achieve higher productivity, filing should be cross stroke(Fig. 111, b).
With such processing, the plane of the part is first filed from right to left at an angle of 30-40 ° to the side of the vise, and when the plane is filed, filing from left to right is performed in the same order. This operation is repeated until the desired layer of metal is removed.
Circular strokes(Fig. 111, c) remove the protruding parts of the metal.
Rice. 111. filing technique:
a - longitudinal oblique stroke, b - cross stroke, c - circular strokes
When cutting, it is necessary to observe following rules:
1) fix the workpiece in a vice in a horizontal plane so that it protrudes 8-10 mm above the level of the vise jaws. A higher position, especially of thin parts, causes instability and vibrations;
2) remove thick layers of metal (allowance) with a chisel. This will not only save time, but also save files;
3) use one side of the file, and use the other side only after the first side is blunted;
4) do not touch the surface to be filed with your hand, as grease and sweat from the hand create a slippery surface that is difficult to file;
5) use files only for their intended purpose: it is impossible to file soft metals (lead, tin, etc.), as well as rough workpieces with personal files;
6) when filing small surfaces, the entire length of the file should be involved in the work.
Virtually any metal part made manually at home, requires filing, in which the excess layer of metal is cut off file- a steel bar with a notch.
Depending on the shape of the section, files can be flat, semicircular, square, trihedral, round, rhombic (Fig. 9).
Rice. 9. The most common files and their application: a - flat; b - semicircular; c - square; g - trihedral; d - round.
In size, files are distinguished large (up to 400 mm) and small files - needle files. In addition, files can have single (simple), double, rasp and arc notches (Fig. 10).
Rice. 10. File: a - elements of the file; b - notching methods.
A simple (single) notch allows you to remove wide chips along the entire length, so the main use of such tools is the processing of workpieces made of soft metals and alloys (lead, brass, bronze, copper, etc.). In addition, these files are used for sharpening saws. Double-cut files are used for processing steel, cast iron and hard alloy parts.
The rasp notch is a pyramidal projections and grooves arranged in a checkerboard pattern, resulting in rather large and rare teeth. Rasp cut files are designed for roughing soft materials.
The arc notch has a greater, in comparison with others, resistance.
Many arc-cut files have different pitches, so they can remove large and small chips at the same time. Therefore, the surface of the workpiece treated with such a file is cleaner. Depending on the size of the notches and the step between them, all files are divided into six numbers.
No. 0 - bars - files with a very large notch for rough processing with the removal of a large layer of metal.
No. 1 - bastard files for less rough processing (cutting allowances, chamfering, burrs, etc.).
No. 2–4 - personal files for processing and finishing metal after using a bastard file.
No. 5 - velvet files for the most precise processing and finishing of surfaces.
For the convenience of working on the file shank, it is recommended to put on a handle made of wood (birch, ash, maple).
For accurate special works files with a very fine notch are used - needle files. With their help, they perform patterning, engraving, jewelry work, cleaning in hard-to-reach places matrices, small holes, profile sections of the product, etc.
The material for files of all types is carbon tool steel, starting with grades U7 or U7A and ending with grades U13 or U13A.
Extending the service life of the file is ensured by proper use and care of it. So, for example, it is impossible to file with a file materials whose hardness exceeds the hardness of the tool itself. With a new file, soft metals should be processed first, and after some blunting, harder ones. Do not hit the files: due to their brittleness, they can crack and break. Do not place a file on metal objects: This may cause the teeth to fall out.
From the book: Korshever N. G. Metalwork
The direction of movement of the file, and consequently, the position of the strokes (file trace) on the machined surface can be longitudinal, transverse, cross and circular.
Working with a file only in the longitudinal or only in the transverse direction, it is difficult to obtain a correct and clean surface of the workpiece.
When filing transversely, the file removes a layer of metal faster than when filing longitudinally, since it comes into contact with a smaller surface area and cuts into the metal more easily. Therefore, to remove large allowances, it is better to use transverse filing (Fig. 81, i). The filing process in this case can be completed by placing a longitudinal stroke on the surface to be treated (Fig. 81, b). The combination of transverse and longitudinal filing of the edge allows you to achieve the right degree its straightness in the longitudinal direction.
Good results in terms of productivity and surface quality when processing planes are achieved when filing with a cross (oblique) stroke; the movement of the file is transferred in this case alternately from corner to corner (Fig. 81, c). Usually, the plane of the workpiece is first filed from right to left at an angle of 35-40 ° to the side of the vise, and then also from left to right. When filing with a cross stroke on the surface of the workpiece, the mesh formed by the teeth of the file must be preserved all the time. This grid controls the quality of work; the absence of a grid on any part of the surface indicates the wrong position of the file in this place.
Filing with circular strokes is carried out in those cases when it is necessary to remove protruding parts of the metal from the surface to be treated (Fig. 81, d).
Fine sawing and surface finishing. When filing, not only the specified accuracy of processing is ensured, but also the necessary cleanliness of the surface finish. A rough finish is achieved by processing with a bastard file with a fine notch, a more thorough one - with personal files. The most perfect finish is achieved by processing with velvet files, paper or linen abrasive paper, abrasive stones, etc.
When finishing the plane with velvet files, filing is done with longitudinal and transverse strokes with light pressure on the file (Fig. 82, a). After finishing with a file over-
Nost, as needed, is treated with abrasive bars and skins, dry or with oil. In the first case, a shiny metal surface is obtained, in the second - semi-matt. When finishing copper and aluminum, the skin is rubbed with stearin.
For surface finishing, wooden blocks with abrasive sandpaper glued to them are also used (Fig. 82, b, c). In some cases, the skin is wrapped around a flat file.
Files are cleaned from chips with steel brushes, as well as special scrapers made of steel or brass wire with a flattened end (Fig. 82, d). When cleaning files from rubber, fiber and wood chips, they are first dipped in hot water for 15-20 minutes, and then cleaned with a steel brush. Oily files are cleaned with a piece of birch charcoal, with which the surfaces are rubbed along the rows of notches, and then cleaned with a steel brush. If such cleaning proves ineffective, the oily file should be washed in a hot caustic soda solution, cleaned with a steel brush, rinsed in water and dried.
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filing metal
General tricks and filing rules
The workpiece to be sawn is clamped in a vice so that the surface to be treated protrudes above the vise jaws to a height of 5 to 10 mm. The clamp is made between the muffs. The vise should be installed according to the height of the worker and well fixed.
When filing, one must stand in front of the vise on the left or right, depending on the need, turning 45 ° to the axis of the vise. The left leg is pushed forward in the direction of the file, the right leg is set aside from the left by 200-300 mm so that the middle of its foot is against the heel of the left leg.
Rice. 1. Filing: a - the normal position of the body of the worker, b - the layout of the legs, c - the position of the body of the worker with heavy filing
The file is taken in the right hand by the handle (Fig. 2), resting its head on the palm; the thumb is placed on the handle along, with the rest of the fingers supporting the handle from below. Putting the file on the workpiece, lay the left hand with the palm across the file at a distance of 20-30 mm from its end. In this case, the fingers should be half-bent, and not tucked in, since otherwise they can be easily injured on the sharp edges of the workpiece. Raise the elbow of the left hand. The right hand, from the elbow to the hand, should form a straight line with the file.
Rice. 2. Techniques for working with a file: a - the position of the file handle in the right hand, b - filing, c - the position of the left hand on the file
Actions of hands during sawing. The file is moved with both hands forward (away from you) and back (towards yourself) smoothly, for its entire length. When moving the file forward, they press it with their hands, but not equally. As it moves forward, they increase the pressure of the right hand and weaken the pressure of the left (Fig. 3). When moving the file back, do not press on it.
When filing planes, the file must be moved not only forward, but at the same time move it sideways to the right or left in order to cut a uniform layer of metal from the entire plane. The quality of filing depends on the ability to regulate the force of pressure on the file; this skill is achieved only in the process practical work for sawing.
If you press the file with a constant force, then at the beginning of the working stroke it will deviate with the handle down, and at the end of the working stroke - with the front end down. With such work, the edges of the treated surface will “fill up”.
Sawing methods. The hardest part about filing is getting a smooth surface. The difficulty lies in the fact that the filer does not see whether he really shoots in this moment that layer of metal and in the place where it is necessary.
It is possible to correctly file a plane only if a file with a straight or convex, but not concave surface is selected and if filing is performed by moving the file crosswise (oblique stroke), i.e. alternately from corner to corner. To do this, filing is first carried out, for example, from left to right at an angle of 30-40 ° to the sides of the vise. After the entire plane has been traversed in this direction, it is necessary, without interrupting work (so as not to lose pace), go to filing with a straight stroke and then continue filing again with an oblique stroke, but from right to left. The angle is kept the same. As a result, a network of cross strokes is obtained on the plane.
By the arrangement of the strokes, you can check the correctness of the machined plane. Suppose that on a plane sawn from left to right, by applying a test ruler, a bulge was found in the middle, and a blockage along the edges. It is obvious that the plane is filed incorrectly. If now we continue filing by moving the file from right to left so that the strokes lie only on the bulge, then such filing will be correct. If the strokes are indicated both on the bulge and on the edges of the plane, this will mean that the filing is again being done incorrectly.
Finishing of the processed surface. The filing of the surface usually ends with its finishing, which is produced different ways. AT plumbing surfaces are finished with personal and velvet files, paper or linen abrasive skins, abrasive bars. Finishing with files is done with transverse, longitudinal and circular strokes.
In order to obtain a smooth and clean surface as a result of finishing, it is very important not to allow deep scratches when pre-finishing sawing. Since scratches are obtained from sawdust stuck in the notch of the file, it is necessary during work to clean the notch more often and rub it with chalk or mineral oil. Even more carefully it is necessary to clean and rub with chalk or oil (and when filing aluminum with stearin) the notch of the finishing files, especially when working on viscous metals.
After finishing with a file, the surface is treated with abrasive stones or abrasive sandpaper (small numbers) dry or with oil. In the first case, a shiny metal surface is obtained, in the second - semi-matt. When finishing copper and aluminum, the skin should be rubbed with stearin.
Rice. Fig. 3. Distribution of the vertical clamping force of the right and left hands on the file (different pressing force is shown by the arrows, respectively). different sizes);: a - at the beginning of the movement, b - in the middle of the movement, c - at the end of the movement
Rice. 4. Checking the file for straightness
Sanding a flat surface requires skill; incorrect work with sandpaper can lead to damage to the product. For surface finishing, wooden blocks with abrasive sandpaper glued to them are also used. Sometimes the skin is screwed onto a flat file (in one layer) or a strip of skin is pulled over the file, holding it while working, as shown in Fig. 7, e.
Rice. 5. filing; a, b and c - successive positions of the worker, d - movement of the file during filing
When finishing a curved surface, as well as in those cases of finishing a straight surface, when a possible small blockage of the edges will not be considered a marriage, the skin is wrapped on a file in several layers.
Rice. 6. Finishing the surface with a file: a - transverse stroke, b and c - longitudinal stroke, d - circular stroke
Measurement and control when filing. To make sure correct filing plane, it is necessary from time to time to check it with a test ruler for clearance. If the ruler lies tightly on the plane, without a gap, this means that the plane has been filed cleanly and correctly. If an even clearance along the entire length of the ruler is indicated, the plane is filed correctly, but roughly. Such a gap is formed because the notch of the file leaves thin grooves on the metal surface and the ruler rests on their tips.
Rice. 7. Finishing sawn surfaces. a - wooden bars with glued sandpaper, b - surface finish of the part wooden block, c - abrasive paper sandpaper stretched on a file, g - finishing the concave surface with abrasive sandpaper
On an incorrectly sawn plane, when applying a ruler, uneven gaps will be found.
Checking for clearance is carried out in all directions of the controlled plane: along and across and from corner to corner, i.e. diagonally. The ruler must be held with three fingers of the right hand - thumb, index and middle. You can not move the ruler along the plane being checked: it wears out from this and loses its straightness. To move the ruler, it must be lifted and carefully placed in a new place.
When checking with a square, it is carefully and tightly applied with the long side to the wide plane of the part; the short side is brought to the side to be checked and looked at the light If the part on this side is filed correctly, the short side of the square will lie tightly across the side of the part. In case of incorrect filing, the square will touch either only the middle of the side (if this side is convex), or some edges (if the side is oblique).
To check the parallelism of two planes, use a caliper. The distance between parallel planes in any place must be the same. Caliper hold right hand for the swivel washer. Setting the solution of the legs of the caliper to a certain size is done by lightly tapping one of the legs on some hard object.
The legs of the caliper must be installed on the parts so that their ends are opposite each other. When oblique installed legs, offsets, and slopes, the test will produce incorrect results.
To check, set the solution of the legs of the caliper exactly according to the distance between the planes in any one place and move the caliper over the entire surface. If, when moving the caliper between its legs, a pitching is felt, this means that in this place the distance between the planes is less; if the caliper moves tight (without pitching), this means that the distance between the planes in this place is greater than in another.
K category: Plumbing work
Metal filing techniques
The sawn product is firmly clamped in a vice to give it a stable position.
A layer of rust and scale on the workpiece and the crust of the casting are filed with an old bastard file so as not to spoil the good one, which wears out quickly. Then they start roughing the part with a suitable bastard file and then finish it with a personal file.
Rice. 1. The position of the worker at the vice: a - the position of the body, b - the layout of the legs, c - the position of the body during rough filing
In order not to spoil the vise jaws during the final filing, they are put on overlays made of copper, brass, lead or aluminum.
The frequency and accuracy of filing depends on the installation of the vice, the position of the body of the worker at the vice, working methods and the position of the file.
The top of the vise jaws should be at the level of the worker's elbow. The correct position of the vise worker is shown in fig. one.
The person working when filing should stand on the side of the vise - half-turned, at a distance of about 200 mm from the edge of the workbench. The body must be straight and rotated 45° to the longitudinal axis of the vise. The legs are spaced to the width of the foot, the left leg is extended slightly forward in the direction of the file. The feet are placed approximately 60° apart. When working, the body is slightly tilted forward. This position of the body and legs provides the most comfortable and stable position for the worker, the movement of the hands becomes free.
During filing, the file is held with the right hand, resting the head of the handle in the palm of your hand. The thumb is placed on top of the handle, and the rest of the fingers support the handle from below. left hand put on the end of the file near his nose and press the file.
When rough filing, the palm of the left hand is placed at a distance of about 30 mm from the end of the file, fingers half-bent so as not to injure them on the edges of the product during operation.
When finishing filing, the end of the file is held with the left hand between thumb located at the top of the file, and with the other fingers at the bottom of the file. The file is moved back and forth smoothly along its entire length.
The product is clamped in a vise so that the sawn surface protrudes 5-10 mm above the vise jaws. In order to avoid recesses and blockages along the edges, when moving the file forward, it is evenly pressed against the entire surface being processed. The file is pressed only when moving it forward. With the reverse movement of the file, the pressure is weakened. The speed of the file is 40-60 double strokes per minute.
To obtain a properly processed plane, the product is filed with cross strokes alternately from corner to corner. First, the surface is filed from right to left, and then from left to right. Thus, the surface is sawn off until the necessary layer of metal is removed.
After the final filing of the first wide plane of the tile, they begin filing the opposite surface. In this case, it is required to obtain parallel surfaces of a given thickness.
The second wide surface is filed with cross strokes.
The accuracy of the surface treatment and the accuracy of the corners are checked with a ruler and square, and the dimensions are checked with a caliper, inside gauge, scale ruler or caliper.
When preparing pipelines and manufacturing parts for sanitary systems, the ends of pipes and the plane of parts are sawn off. When filing products, it is necessary to strive to prevent marriage. Marriage during filing is the removal of an excess layer of metal and a decrease in the size of the product compared to the required ones, the unevenness of the sawn surface and the appearance of "blockages".
Therefore, before starting filing, the locksmith must carefully mark the product and choose the right files. In the process of filing, you should use control and measuring tools and systematically check the dimensions of the workpieces.
To extend the service life of files, it is necessary to clean the file notch from stuck chips in a timely manner and protect it from oil and water. The file is cleaned of dirt or metal particles with steel brushes.
Do not take the working part of the file oily hands and put the files on the oil workbench.
When filing soft metals, it is recommended to rub the file with chalk beforehand. This will prevent it from being clogged with metal filings and will facilitate cleaning from sawdust.
When filing, the following safety rules must be observed: - the handle must be firmly attached to the file so that during operation it does not come off and injure the hand with the shank; - the vise must be in good condition, the product must be firmly fixed in them; - the workbench must be firmly fixed so that it does not swing; - when filing parts with sharp edges, do not press your fingers under the nozzle during its reverse stroke; - shavings are allowed to be removed only with a sweeping brush; – after work, the files must be cleaned of dirt and chips wire brush; - it is not recommended to put files one on top of the other, as this spoils the notch.
For the mechanization of filing work, an electric filing machine with a pneumatic drive and a flexible shaft is used. A special device is put on the end of the flexible shaft, which converts rotational motion into reciprocating motion. A file is inserted into this device, with which parts are filed.
- Techniques for filing metal