In the arsenal of both home and professional masters there should be many different tools. Drills are irreplaceable for implementation of the whole range of works. Today there are many varieties. However, the twist drill is the most widely used. This is due to a number of its features and functions. The device of this tool, as well as the scope of its application, deserve special attention.
General information
A drill is a cutting element of a tool that makes holes in various materials. There are many varieties of them. The type of cutter is selected based on the characteristics and working conditions. According to the characteristics of a hammer drill, drills must be harder than the material.
The purpose of the drills is different. They can be used for processing metal, wood, concrete, glass, tiles. Each tool, depending on the purpose, has its own characteristics.
Twist drill is the most widespread today. It is also called screw. It has a cylindrical shape and has a number of design features.
Drill device
Drillspiral has three main elements. This is the working part, shank and neck of the cutter. In the first section there are two spiral helical grooves. This is a cutting element. They are also good at removing chips from the workplace. If the technique has such an opportunity, it is through these grooves that lubricant is supplied to the drilling area.
The working part consists of cutting and calibration department. The latter is also called a ribbon. This is a narrow strip that continues the surface of the groove on the cutter. The cutting department consists of two main and two auxiliary edges. They are located along the cutter cylinder in a spiral. Also referred to this part is the transverse edge. It has a conical shape and is located at the end of the drill.
To be securely fixed in the machine or hand tool, the cutter has a shank. It may have a foot for removing the drill from the socket or a leash. The latter provides torque transmission from the tool chuck.
The neck is needed to exit the abrasive wheel when grinding the working part.
Product Features
Drills for a perforator, machine tool, which have a spiral shape, are the most popular today. This is due to their special characteristics. They are well guided in the hole and also have a large margin for regrinding. Due to the design features, such a cutter removes chips well and easily supplies lubricants to the working surface. These features make this type of drill very popular.
Forthe correct designation of geometric parameters has its own designations. The diameter of the drill in this case can be very different. However, the designations remain the same. The tip angle at the top is referred to as 2φ. The slope of the grooves is indicated by the letter ω, and the end transverse edge - ψ. The front angle in the drawings is referred to as γ, and the back - α.
All together these indicators are called drill geometry. It reflects the position of the grooves, cutting edges, as well as their angles.
Tool Varieties
The classification of cutters takes into account such an important indicator as the shape of the shank. It can be of the following varieties:
- Cutter with cylindrical shank (GOST 2034-80).
- Drills with tapered shank (GOST 10903).
- Tool with tapered shank (GOST 22736).
In order for the master to be able to complete all the tasks assigned to him, the drill is produced in various types. In the first version, the cutter is mounted in a three-jaw chuck or other intended fixture.
Twist drill with cylindrical shank can be made in short, medium and long versions. Such a tool has 3 accuracy classes: increased (A1), normal (B1) and normal (B). They can be made both welded and in one piece. The shank must not have ring cracks, lack of fusion or surface pitting.
Conical varieties are mounted directly in the equipment spindle or transitionalsleeve (if the size does not match).
Taper shank
The taper shank cutter shown here uses several different standards. The twist drill (GOST 10903) is applicable for products of normal length. This group also includes several more standards that are used in the manufacturing process of long, elongated cutters. These instruments are available with or without a neck. Moreover, its size is not regulated in any way.
Cutter with a tapered shank (GOST 22736) regulates the production of products with a diameter of 10-30 mm, which have a carbide insert. They can be made short or normal. The accuracy class for these products can be increased (A) and normal (B).
Drills with a tapered shank with a diameter of more than 6 mm are made by welding. For narrower sections it is allowed to use a one-piece type of manufacture.
Metal Drills
In addition to the breakdown of cutters according to the principle of the shape of the shank, there is a classification according to the material of processing. The cutter can be designed for metal, concrete, there is also a drill for wood. The spiral work station is applicable to all kinds of material. The difference lies only in the design of the tool.
Depending on the type of metal, the type of drill is selected. They are applicable to alloyed, non-alloyed steels, cast iron, alloys, non-ferrous metals. Sometimes they are used for processing hard plastics. Fromthickness and hardness of the working area depends on the durability of the product. This is a universal type of instrument. A metal drill can fully drill a hole even in wood.
If the tool sinks slowly and heats the material strongly, it needs to be sharpened. If its diameter does not exceed 12 mm, the procedure is carried out manually. But for a larger cutter, special equipment is used for sharpening.
Concrete drill
One of the most difficult materials to process is concrete. It requires the use of tools with special carbide inserts. They are called victorious. Today, any carbide bits are referred to in this way.
Such a tool in the process of processing the material leaves holes with a diameter larger than the drill itself. It has to do with his beating. If a drill is used, the drill shank may be cylindrical. A different type of fastening is used for a puncher. It's called SDS. There are several types of them. Such a system allows you to quickly change the nozzles in the puncher and other equipment.
It is possible to sharpen such drills. However, be careful not to overheat the tool. Otherwise, the carbide insert may fall off.
Wood drill
A suitable wood twist drill is made from ordinary high-strength steel. Such material does not put forward serious requirements for the material of the cutter, its shape. This is the most common drill. Pretty easy to screw into softwood or chipboardordinary screw. This does not require a drill. However, there are situations where it is indispensable.
If you want to make a hole up to 600 mm deep, you should use a helical version of the cutter. Their diameter can be from 8 to 25 mm. Their length may be different. This is convenient if you need to make a non-through or through hole. If required, use an extension cord.
When drilling, the drill after several revolutions is taken out of the material, cleaned of chips. Then they continue to work. Their length can be 300, 460 and 600 mm.
Familiarizing yourself with the main characteristics and method of using such a tool as a twist drill, everyone can choose the right variety for themselves. This is a very popular type of cutter. Their unique qualities, wide range of applications make them very popular.
