Concrete is one of the most durable materials, therefore it is very difficult to drill even the smallest hole in it. As a result, a tool for drilling must possess enhanced technical characteristics. For these purposes, drill bits for concrete are improved with cemented metal carbide tips. The cutting surface of such a product has reverse sharpening.
Peculiarities of SDS plus drill bits for concrete
The main material for production of carbide inserts is the alloy based on tungsten and cobalt. Modern technologies make it possible to produce inserts from the improved tungsten-cobalt alloy. This allows you to make holes in:
- ceramic tiles.
The main feature of drill bits is the shape of their shanks. They have several grooves designed to transmit shock vibration effectively as well as rotation.
There are five types of SDS shanks, however, only two of them have gained popularity: SDS max and SDS plus. There are differences between them, for example, the first has five grooves, and the second has four. The thickness of SDS plus drill bits is almost half that of Max ones. SDS plus shanks are installed on core drill bits or bore bits with a diameter of 26 mm.
Most large drills have a head in the form of a shovel with equal edges, which are sharpened at an angle of more than 90 degrees. However, during drilling a large uncertainty in diameter is observed, while the drill bit heats up and loses its original quality. Such a tool cannot cope with high-strength concrete.
Thanks to some research it has become possible to create a drill bit with a tetrahedral and even hexagonal working head. The structure of its tip is more complex than in the previous case, however impact load is distributed evenly. Such drill bits are used for processing reinforced concrete. High strength and an optimal sharpening angle make it possible to grind even metal rods as well as to minimize uncertainties.
Classification of drill bits by diameters
SDS plus drill bits have only even diameters, with a minimum of 6 mm and a maximum of 26 mm. You can find drills thickness of 4 or 5 mm but finding an appropriate tool is very difficult. Each diameter is directly dependent on length.
Drill bits less than 12 mm are used to create holes in fixing systems. Drills with a larger diameter are used to equip technical communications. The dimensions of standard SDS-Max indicate that this tool is designed for deep hole drilling. Their thickness is in the range of 12-50, with a length of 600-1000.
You can find longer drill bits, experts often use special extension cords. The tool is great for arranging technical channels directly in concrete. It is important to note that the drills of this line belong to the professional series, they are not used at home, since a conventional hammer drill is not able to provide sufficient power.
Service life of drill bits
Each experienced DIYer knows well-known brands that produce high-quality, reliable and durable tools. Drill bits are produced by companies such as Keil, Hilti, Alpen, Makita etc. Bosch and AEG are considered as more reputable. The country of origin matters little. Even Chinese products can have a high quality. When choosing a tool, you need to pay attention to the availability of a certificate from the manufacturer.
The durability of the product is affected by drilling methods. Too much force and lack of control when working with a drill lead to damaging guide grooves and a shank. These problems are indicated by loss of a drill bit from a working chuck.
Drilling a large number of holes of small depth is better carried out using a drill bit with different edges. Such a product is easily sharpened on an emery stand. The processing of denser materials is carried out using multifaceted type heads. More expensive models went through hardening and several sharpening stages, so that the tool is not erased. Specialists call this function self-sharpening.
SDS plus drill bits for concrete have a large number of advantages that allow an ordinary user to operate with this tool at home. You need to determine the hole diameter and then choose the drill bit length. Luboil on the spindle and shank prevents material from overheating.