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What are the forms of scrapers. Scraper and scraping are all about them. Product Specifications

In appearance, an unremarkable tool - a bench scraper - is considered very necessary in most areas of production where it is necessary to bring the surface to perfect smoothness. What kind of device is it and how to use it, we will learn a little lower.

What does the unusual word scrapery mean?

This word means just the process of using the above-mentioned tool. As experienced locksmiths say, work is not easy and requires jewelry accuracy, scrupulousness, patience and, of course, skill. The skill does not come right away, and many details remain spoiled before the young locksmith masters this tricky operation, and by the way, it takes up almost 20% of all tasks in plumbing. So you can’t get around it in any way. The required dexterity can be judged by the fact that in one pass, a maximum of 0.7 mm of metal can be removed, and with an average effort it will take no more than 0.03 mm.

Scraping consists in the fact that a barely visible top layer is removed from the workpiece. Most often, they work with metal, although the same technique is often encountered when processing wood, but with this more obedient material you can work with other cutting tools, reaching a smooth surface. Not everything is so simple with metal, and only scraping gives a really desired result. A metal scraper is capable of removing even almost imperceptible roughnesses that prevent friction surfaces from carrying out the stable operation of mechanisms.

After this treatment, the parts can fit snugly together, lubricate well, and not lose lubrication. Removing a thin rough layer makes it possible to perfectly fit the part size to the required one.

A set of scrapers is in every locksmith's workshop; such tools are necessary even in the manufacture of calibration devices to give them a smooth surface to squeak. In addition, it is possible to successfully process a curved surface, however, this task is even more complicated and requires appropriate qualifications and experience, especially if the arsenal contains only a manual model of a device for scraping. In this way, the details of the various devices, the guides of the machines, are aligned, and even the bearings can be brought into perfect shape using such tools.

Types of scrapers - what might surprise such a simple tool?

Types of scrapers are distinguished by several criteria. For example, by design, devices can be divided into integral and composite. It’s not difficult to guess the difference between them. Despite the external simplicity, there are differences in the shape of the edge, which is the direct work. So, they distinguish flat (the simplest form is a straight plate), shaped (the plate has the shape of the part that is planned to be processed) and trihedral. There are also different numbers of cutting faces, there can be two (double-sided tools for scraping) or one (single-sided).

As you can see, the components of this cutting device are not many, but you can get lost in them. And if you look around in a modern hardware store, you will see that in addition to these criteria, there is another significant nuance - the drive. Yes, today you can work not only with your hands, or rather, you still have to control them, but you don’t need to strain, because there are already other types of tools - pneumatic, electric scraper for metal and manual, of course. The working surface of all such devices is made of carbon, usually these are grades U10-U13, less often - from some kind of hard alloy.

How to choose the same scraper from a huge set?

As you can see, the choice is great, but how to decide which of the proposed tools to take for work? If you are faced with the task of leveling the surface of a flat object or part, then a straightforward device is quite suitable, the number of cutting edges can be any, attach the one that you like best. If there is no rectilinear, then curvilinear will do for this task. The main component of successful work is the correct sharpening of the cutting edge, the geometry in such cases is determined by how rough the processing is planned, i.e. how many millimeters of material we need to remove, also from the hardness of this material and from the angle of the cutting edge relative to the surface we are processing.

Typically, the sharpening angle is 90-100 °, which is easiest to work with. But if you have only a rough stage of processing, then the angle can be from 75 °, when the finishing stage is already done, the maximum angle is taken - 100 °. As for the materials, for soft metals you can sharpen the tool even by 35-40 °, but for steel you need an angle of 75-90 °, and if you have cast iron or bronze in front of you, prepare a tool with a sharpening under 90-100 °. When choosing the width and radius of rounding for your cutting tool, also rely on the hardness of the material being processed and on the requirement for clean work. The rule is this: with high hardness and purity of grinding, the cutting edge should be narrow (draft stage - up to 3 cm, and finishing - 1.2 cm) and with a small rounding radius.

For special cases, for example, for curvilinear work on the processing of bearings, they take a trihedral tool, and sharpen it by 60 °. And if there is a lot of work to be done, and it is rather varied, then a lot of devices are needed, then it is easier to use a compound tool for scraping. In it, you can simply change the plates, and this is done elementarily, only by unscrewing the clamping screw. In some cases, locksmiths do not quite look at such a tool - in the form of a ring. It is much more convenient for them to grind a round detail.

Learning to use the scraper tool

Having learned a lot about this process and tool, it's time to see how to use the scraper.

  - This is the final locksmith operation, which consists in scraping very thin layers of material from the surface of the workpiece using a cutting tool - a scraper. Scraping is used in cases where it is necessary to process surfaces with very low roughness. As a rule, mating surfaces undergo mating surfaces moving relative to each other (rubbing surfaces). With its help, a snug fit of the mating surfaces, reliable retention of lubricant between the rubbing surfaces and the exact dimensions of the parts are achieved.

Both flat and curved surfaces (for example, machine guides), surfaces of sliding bearings, parts of devices, and also surfaces of various tools and devices (for example, calibration plates, squares, rulers) are processed by scraper. In one pass, the scraper can remove a very thin metal layer with a thickness of not more than 0.7 mm from the surface of the workpiece. With medium effort applied to the tool, the thickness of the removed chips is 0.01 ... 0.03 mm.

Scraping is a very time-consuming operation  and requires extremely highly qualified locksmiths. In the practice of locksmithing, scrapping takes about 20%, therefore, mechanization of labor and the replacement of manual scrapping with machine tools are of great importance.

Tools and devices for scraping. Scrapers

The scraper is the cutting tool. Scrapers vary in design  - one-piece and composite, the shape of the cutting edge - flat, trihedral and shaped, as well as the number of cutting faces - one-sided and two-sided.

Scrapers are made fromcarbon tool steels of grades U10 ... U13. Composite scrapers can be equipped with high speed steel or carbide inserts.

To scrape flat surfaces, one- or two-sided scrapers with a straight or curved cutting edge are used (Fig. 4.3, a, b, c). The geometric parameters of the scrapers depend on the type of processing, the material of the workpiece and the angle of installation of the tool with respect to the surface being machined. The end surface of the scraper is sharpened at an angle of sharpening 90 ... 100 ° relative to the axis of the tool. When roughing, the angle of sharpening is 75 ... 90 °, when finishing - 90 °, and when finishing - 90 ... 100 °. The point angle for cast iron and bronze is chosen equal to 90 ... 100 °, for steel - 75 ... 90 °, and for soft metals - 35 ... 40 °.

The choice of the length of the cutting edge and the radius of its rounding depends on the hardness of the processed material and the given roughness of the machined surface. The harder the material being processed and the higher the requirements for the cleanliness of the processed surface, the narrower the cutting edge of the scraper should be and the smaller the radius of curvature.

For rough scraping, scrapers with a cutting edge width of 20 ... 30 mm are used, for finishing - 15 ... 20 mm and for finishing - 5 ... 12 mm.

For scrapping concave surfaces, for example plain bearing shells, trihedral scraper designed  (Fig. 4.3, d), which have three cutting edges and can be straight and curved; their point angle is 60 °. These scrapers have longitudinal grooves (grooves) on their faces, which makes sharpening and refueling more convenient.

In addition to solid ones, compound scrapers are used (Fig. 4.3, e), allowing to quickly replace the cutting inserts, and therefore convenient for performing various scraping work. Such a scraper consists of a holder body 2, a handle 4 and a clamping screw 3. A replaceable cutting insert 1 of carbon, high speed steel or hard alloy is fixed in the holder 2 by rotating the screw 3 with the handle 5.

In a simpler design of the scraper (Fig. 4.3, f), the cutting inserts 6 are fixed in the handle 7 with a nut.

When scrapping loose leaf bearings, to reduce the number of regrindings during operation, scraper rings are used (Fig. 4.4), which can be made from a worn tapered roller bearing ring.

Since scraping is the final operation of metalwork, the quality of its implementation must be monitored throughout the process. For these purposes, verification tools are intended.

Testing tools (Fig. 4.5) include: test plates for monitoring wide flat surfaces; flat test rulers (Fig. 4.5, a, b) used to control the scraping of long and relatively narrow flat surfaces; trihedral angle rulers (Fig. 4.5, c) used to control scraping of surfaces located at an internal angle, corner plates - to control the quality of scraping of surfaces at right angles; as well as test rollers - to control the scraping of cylindrical surfaces and recesses. The quality control of scraping with all of these tools is based on identifying irregularities on the surface treated with scraping. Irregularities on the surface to be treated become visible after applying it to the painted test tool or vice versa, after applying the painted tool to the treated surface and moving them relative to each other.

It is very important that the test tools are kept in proper condition, therefore, after work, the test tool should be cleaned, lubricated and only then put into a case or covered with a lid.

Scraper. Do you know this word? Most of us may have heard it for the first time. But did you know that this word simultaneously represents instruments from different spheres and branches of human activity? What kind? Let's find out together.

In contact with

Shaber: what is it?

First of all, let's see how this device is used in locksmith work. So, the scraper in this case is a tool that the locksmith nowadays is widely and actively used for finishing the surfaces of mechanical parts.

What benefits does this building tool bring? In fact, he plays an important role in such works. It successfully performs its primary function. It also well cleans the metal surface of existing irregularities. Thus, the surface becomes smooth and comfortable for further work.

Locksmith design

The design is as follows:

  • Lever. The handle can be either trihedral or tetrahedral.
  • Cutting part.

It is customary to make all these necessary devices for performing locksmith work out of tool steel. They have a standard length, namely 20 - 40 cm. But the width of the cutting part directly depends on the type of work performed. Also, the type of work affects what kind of grinding angle will be used by specialists. For example, during finishing operations it is customary to use a sharpening of 90 degrees. But, for roughing, it is better to arm with a device with a sharpening of 75 degrees.

Often, the edge angle is measured taking into account its axis.

Areas of use

Such locksmith devices today are successfully used for various metal structures. In most cases, they are used for:

  • Blades of cutting tools. Sharpener - scraper is suitable for blades.
  • Manufacture of machine parts and parts of high-precision devices.
  • Production of a wide variety of measuring tools.
  • The manufacture of elements of bearings.
  • Manufacture of special devices that carry out control operations.

For the mentioned works, experienced specialists use different types of devices. So let's get acquainted with the existing types of this bench tool.

Types of locksmiths

There are several types. They differ in appearance. The differences between them determine the following parameters:

  • The shape is the cutting part. The shape of the cutting part distinguishes these types:
    1. Trihedral.
    2. Flat.
    3. Shaped.

Each form of the cutting part is used in specific cases and has its own characteristics. So, for example, unlike flat trihedral scrapers, shaped ones are able to completely repeat the shape of the surface that is being processed. Therefore, it can be considered more convenient.

As for the necessary advantages, the scraper has a lot of them. The main one is universality. As shown, it can be used to work with a wide variety of metal surfaces and structures.

Scraper how it looks




However, not only such a bench tool is called a scraper. A similar word is often found in other areas. For example, in manicure.

Scraper for manicure

As you know, it is thanks to good manicure and subsequent care that it is possible to maintain your nails in good condition. Some procedures are able to perform some on their own. Others prefer to seek help in special salons. But no matter where, how, and by whom the manicure procedures are carried out, it is necessary to have certain tools with you.

Today, special manicure sets are sold. Often, such a set consists of the following tools:

Of all the above, the scraper is less known. Let's get to know him better.

What is a scraper in manicure?

First of all, a manicure scraper, of course, differs from a bench tool. Moreover, it differs not only in appearance, but also in the purpose of use. If the bench tool is intended for metal and wooden surfaces, then using a manicure scraper, pterygium (a thin skin that grows and appears under the nail plate) is removed, and the scraper helps to move the cuticle. Thanks to these procedures, nutrients can better and deeper penetrate directly into the root. In addition, the removal of pterygium and cuticle prevents the formation of burrs. Yes, and the hands themselves look pretty beautiful and, no less important, well-groomed.

What is a manicure device made of? Such an important tool in most cases is created from high alloy stainless steel. Externally, the scraper looks like a small stick with a metal structure on the end.

Types of manicure tools

There are several types of manicure scraper. They differ among themselves not only in shape, but also in size. Let us pay attention to some well-known parameters in which one species differs from another:

What is the difference between a scraper and a pusher?

Pusher is another tool that is used in manicure. Often they confuse him with a scraper. It is important to understand that these are two different tools. Since manufacturers often replace one concept with another, you need to understand how they differ. The main difference is in their purpose. The pusher only helps to push the cuticle. The scraper is intended for the final removal of the cuticle. A pusher can not be cut or scraped. It is a safe tool. While a scraper is not recommended to use to someone who is poorly versed in manicure.

At the same time, a scraper is indispensable.

Scraper  - this is a locksmith operation in which the smallest shavings are removed (scraped off) from the surface of the product with a cutting tool - a scraper. Scratch, as a rule, after processing with a cutter, file or other cutting tool.

Scrabble is most often when it is necessary to fit the surfaces of two parts so that they fit together most tightly. So, they will scrape the guides of the bed of lathes, calipers, as well as the surfaces of sliding bearings.

Scraping is a labor-intensive operation that requires a lot of time, since it is necessary to gradually remove very thin layers of metal from the treated surface; with thin scraping, chips with a thickness of up to 0.01 mm are removed in one stroke of the scraper.

To identify which places need to be scraped, the product is placed on the surface of the test plate covered with a thin layer of paint with the processed surface. Gently pushing the product, move it in different directions. As a result, protruding spots on the surface of the product are stained with paint. These places are treated with a scraper.

  Questions

  1. What is called scraping?
  2. What is scrapery used for?
  3. What parts and parts of machines will scrape?

Types of scrapers

Surfaces scrape with one-sided and two-sided scraper.

According to the shape of the working surface, the scrapers are divided into flat, trihedral, shaped. Scrapers are made of carbon tool steel and hardened their cutting part.

According to the shape of the cutting ends, the scrapers distinguish between straight and curved. Flat scraper process straight surfaces.

Curved-end scrapers process surfaces in sharp corners or soft metals (e.g. aluminum).

The double-sided flat scraper serves for the same purposes as the single-sided, but has a longer service life.

The length of flat unilateral scrapers is 200 - 300 mm, and bilateral - 200 - 400 mm. The width of the scraper for roughing and semi-finishing scraping is 20 - 30 mm, for finishing - 15 - 20 mm. The sharpening angle for rough and semi-final scrapers is 60 - 75 °, for fine - 90 °.

Trihedral scrapers, which, as a rule, are released only one-sided, process concave and cylindrical surfaces. Often trihedral scrapers are made from worked trihedral. The length of trihedral scrapers is 100 - 150 mm.

Questions

  1. What are the types of scrapers?
  2. Why use flat scrapers?
  3. Why use trihedral scraper?


  "Plumbing", I.G. Spiridonov,
  G.P. Bufetov, V.G. Kopelevich

In the process, the scrapers are dull; therefore they are sharpened on electric sharpeners with a corundum circle. Sharpening lead the end or side surface of the circle. First sharpen the end, and then the edges of the scraper. Sharpening a flat scraper a - end; b - facets; in - sharpened cutting edges. After this, the scraper is adjusted. When sharpening, press the scraper firmly. Sharpening should be carried out with ...

Locksmiths aimed at ensuring the smoothness of the surfaces of various materials represent a whole group of operations. These include common grinding, sawing, cutting and polishing techniques. The use of abrasives with a varying degree and configuration of graininess combines these methods of finishing surfaces. In many ways, it is similar to them, but scrubbing has fundamental differences. This is a technique that makes it possible to obtain a smooth surface of a workpiece with high accuracy, which in the future will allow the master to ensure its tight coupling with other materials.

Technology Overview

The operation is most often used in relation to metal, but in some cases, plastic and wooden surfaces are treated with similar methods. The essence of the technology is the elimination of pronounced bulges on the product. That is, using a special tool, grinding in irregularities is provided. To understand the degree of accuracy, it is worth noting that the height of the removed layer is calculated in microns. From an operational management point of view, scraping is but not an automated process. It is used but machines and easel mechanisms do not yet have widespread use in this area. A feature of the method is that it is also used in working with non-standard rounded surfaces, where radial slope is required. For example, it can be curved and cylindrical products.

Preparing for Scraping

The use of scraping is due to the tasks of obtaining a highly precise surface in terms of smoothness. Therefore, the use of a specialized tool to achieve such a result when working with materials having a rough surface does not justify itself. Accordingly, the workpieces initially go through the stages of initial cleaning, as well as grinding and even polishing. The demand for recent operations is determined by the parameters with which specific locksmithing works are implemented and, in particular, scraping. Experienced craftsmen practice using calibration details. These are blanks that are exemplary for the resulting product. Also at this stage, auxiliary equipment should be ready, with which the operator will carry out individual technological steps. For example, special primer oil or paint may be used.

Scraping technique

After completing the preparatory processing steps, the first thing to do is apply special paint to the work surface. Its task is to identify the lapping pattern, as well as to identify the most prominent areas on the surface. Sometimes large areas are zoned into separate sections, depending on the complexity of their bringing to the desired state. One way or another, according to the formed pattern, scraping is performed. This means that the processing is not carried out over a continuous area, but in a sense pointwise. The efficiency and quality of the resulting slice is determined by the frequency with which the stripping is performed. After the planned volume of the cut was completed, the master makes another coating of the surface with paint, which again reveals the bulges and irregularities. Thus, quality control of scraping is performed. By the way, the operation cycle can be repeated several times depending on how much each session brings the workpiece surface closer to the sample.

Technical Parameters of Scraping

And in the case of processing flat surfaces, and in fine-tuning curved products, the technology allows to obtain smoothness with an allowance for roughness of the order of 0.002 mm with a length of 1000 mm. For example, a platform measuring 25 x 25 mm 2 may have up to 30 exit-treated spots. The number of spots also determines the level of accuracy of scraping. Thin are considered surfaces on which over 22 spots are present. Conversely, a product with no more than 6 spots on its surface will be considered rough. Again, the number of remaining islets treated with paint will be calculated over an area of \u200b\u200b25 x 25 mm 2. Depending on this parameter, types of scraping are also determined - between a thin and rough cut, precise and final refinements are also distinguished. Which result should be obtained in a particular case depends on the technical task. A thin cut with 30 spots is not always required. Sometimes rough machining is sufficient to fulfill the tightness requirements. But coarse scraping cannot be compared with a similar characteristic when grinding - in both cases we are talking about different orders of height of the remaining bulges.

Tool used

In the classic version, the scraper is a metal rod provided with cutting edges. An important feature of the device is a base made of tool carbon steel. Thanks to such alloys, the metalwork scraper works effectively with most metal products. Also, some models can be equipped with special nozzle plates that differ in different properties - accordingly, the equipment is selected for specific tasks.

It has already been noted that mainly scrapping is carried out with a hand tool. This method allows you to get a high-quality accurate result, but it has a minus - this operation is time-consuming, requires considerable physical effort. Therefore, if special quality requirements are not provided, use pneumatic and electric gauge machines. Mechanized scraping of parts due to the inability to adjust the pressure exerted on the surface does not always provide accurate processing, but it compares favorably with the manual method by the speed of operations.

Pros and Cons of Technology

The main drawback of scraping is the cost and complexity of the process. This is one of the most troublesome locksmith operations, which is resorted to only in special cases. Moreover, even manual equipment involving the use of a simple tool for the device will be expensive because of the need to use consumables in the form of scraper paint. The advantages, which are still many in this processing method, include obtaining a high-precision cut. Other metalwork cannot provide a similar effect (with the exception of technological equipment for grinding and polishing). But in this case, the same drawbacks will occur - grinding machines with increased productivity operate on a different principle and are not always able to achieve a similar quality level of cut. And this is not to mention the cost of the equipment itself, which at a price can be superior to pneumatic and electric scrapers.

Where is the metalwork scraper used?

Practice shows that scraping in the professional sphere of performing locksmithing occupies about 20% of all operations. However, the niche in which products manufactured in this way are used is rather limited. Basically, scrapers are used in the manufacturing processes of parts for machine tools, machines, industrial equipment, etc. It is important not to forget that scraping is a way of obtaining surfaces that are highly accurate in terms of smoothness. Moreover, the surfaces themselves can be curved. For example, high-quality bearings with optimal radial planes can only be obtained in this way.

Conclusion

The difficulty of bringing metal surfaces to a state in which there will be no irregularities even visible to the eye has also determined the high responsibility of the performer himself. The fact is that the highest quality operation (scrapping) involves manual revision, which directly depends on the skills of the master. An experienced locksmith must take into account a lot of nuances in the process. These include the selection of scraper paint, the use of one or another frequency of the tool stroke, and other subtleties that will determine the merits of the final result.