The drill is considered a special cutting device,which features a rotary motion cutting and axial feed. With it, the holes are made in the solid material, the hole diameter increases, and the desired characteristics is obtained recesses if desired. Let's see, how to choose the drill.
Professionals classify the entire set of drillsinto two types: spiral and feather. Each variety has both strengths and weaknesses. Special spiral drill widespread type among buyers. They are made similar to cylinder rod, wherein the two spiral grooves are to the sides of the working part. They serve to remove shavings. In various kinds of drills groove may be inclined at an angle of 10 to 45 degrees. The working end of the drill is made in the shape resembling a cone. The helical type drills shanks are cylindrical, hexagonal, or also have a conical shape.
These types of drills are characterized by long life and excellent reliability index. Now let's talk about their weaknesses, then here include the extremely high price.
Feather drills type and indicators
Perov drills sometimes are called flat. Their design is particularly simple, besides, they are quite affordable, while exploiting their distortion is quite rare. There are bilateral and unilateral drill pore type. Such classification depends on the form in which their sharpened cutting edges.
Feather drills on a variety of cutting portionsprovided with two edges arranged symmetrically along the axis. When they provide cutting corners 45, 50, 75 or 90 degrees. To measure the diameter of the drill just find out what is the width of the blade. Drill diameter determines the thickness of the pen, from which the cutting edges are dependent.
The transverse edge - a straight line formed byat the intersection of the cutting edges. When using feather drills while working impossible to achieve the automatic retraction of chips during drilling operations, the consequence of which is that the cutting edges lose their initial characteristics, and the drill will need to be frequently removed from the hole. When using feather drills they may lose their direction and their diameter decreases regrinding.
Determine the drilling speed
that Choose the Right Drill, You must correctly identify the drilling speed. Maximum efficiency is achieved only when a combination of drill rotation and its supply is optimal. The rotation speed is measured by the number of revolutions per minute. The rate can be defined as the path that the external parts of the cutting edge are per minute.
Many believe that the optimum cutting speeddrilling - a rate which allows a long run and does not require regrinding (up to a half hour) with high performance. If the drill has a diameter up to two centimeters, while it is possible to perform work for 15 minutes. If the diameter of 25-35 mm - 30 minutes if this figure exceeds 40 mm, then the instrument will carry out their functions without regrinding to 90 minutes.
When drilling permissible cutting speed inIt will largely depend on the quality of the material used to build the drill. It is logical that choosing this accessory, it is important to take the time to determine the quality of the material that was used for its production. In the application of high-speed steel cutting speed becomes higher compared to drills made of carbon-metal.
The diameter of the drill bit and drilling depth - important characteristics
Choosing a drill, it is important to determine the desired depthdrilling. Note that with the increase of the characteristics of the problem of diversion of chips is becoming increasingly important, the rate of friction is increased, which contributes to heating of the cutting edges. Therefore, when drilling shallow speed will be higher than for a greater depth of the holes.
It is important to consider the purpose of which is givenholes. They can be cross-cutting, blind to sweep or made under the thread. It is noteworthy that in each of the above cases, to receive the same hole diameter should use the drill, the thickness of which is different. This is due to the fact that, in contact with the edges, the drill hole size increases. We saw the basic rules that will help in the selection of drill bits. Now there is nothing stopping you to go to stroymagazin and pick up the necessary accessories for your drill.