If the high-speed steel twist drill is a microcosm of the global industrial development process, then an electric hammer drill bit can be regarded as the glorious history of modern construction engineering.
In 1914, FEIN developed the first pneumatic hammer, in 1932, Bosch developed the first electric hammer SDS system, and in 1975, Bosch and Hilti jointly developed the SDS-Plus system. Electric hammer drill bits have always been one of the most important consumables in construction engineering and home improvement.
Because the electric hammer drill bit produces rapid reciprocating motion (frequent impact) along the direction of the electric drill rod while rotating, it does not require much hand strength to drill holes in brittle materials such as cement concrete and stone.
To prevent the drill bit from slipping out of the chuck or flying out during rotation, the round shank is designed with two dimples. Due to the two grooves in the drill bit, high-speed hammering can be accelerated and hammering efficiency can be improved. Therefore, hammer drilling with SDS shank drill bits is much more efficient than with other types of shanks. The complete shank and chuck system made for this purpose is particularly suitable for hammer drill bits to drill holes in stone and concrete.
The SDS quick-release system is the standard connection method for electric hammer drill bits today. It ensures optimal power transmission of the electric drill itself and provides a quick, simple and safe way to clamp the drill bit.
The advantage of SDS Plus is that the drill bit can simply be pushed into the spring chuck without tightening. It is not firmly fixed, but can slide back and forth like a piston.
However, the SDS-Plus also has limitations. The diameter of the SDS-Plus shank is 10mm. There is no problem when drilling medium and small holes, but when encountering large and deep holes, there will be insufficient torque, causing the drill bit to get stuck during work and the shank to break.
So based on SDS-Plus, BOSCH developed the three-slot and two-slot SDS-MAX again. There are five grooves on the SDS Max handle: three are open grooves and two are closed grooves (to prevent the drill bit from flying out of the chuck), which is what we commonly call a three-slot and two-slot round handle, also called a five-slot round handle. The shaft diameter reaches 18mm. Compared with SDS-Plus, the design of the SDS Max handle is more suitable for heavy-duty work scenarios, so the torque of the SDS Max handle is stronger than that of SDS-Plus, which is suitable for larger diameter hammer drills for large and deep hole operations.
Many people used to think that the SDS Max system was designed to replace the old SDS system. In fact, the main improvement of this system is to give the piston a larger stroke, so that when the piston hits the drill bit, the impact force is greater and the drill bit cuts more effectively. Although it is an upgrade on the SDS system, the SDS-Plus system will not be eliminated. The 18mm handle diameter of SDS-MAX will be more expensive when processing small-sized drill bits. It cannot be said to be a substitute for SDS-Plus, but a supplement on this basis.
SDS-plus is the most common on the market and is usually suitable for hammer drills with a drill bit diameter of 4mm to 30mm (5/32 inch to 1-1/4 inch), the shortest total length is about 110mm, and the longest is generally not more than 1500mm.
SDS-MAX is generally used for larger holes and electric picks. The hammer drill bit size is generally 1/2 inch (13mm) to 1-3/4 inch (44mm), and the total length is generally 12 to 21 inches (300 to 530mm).
Part 2: Drilling rod
Conventional type
The drill rod is usually made of carbon steel, or alloy steel 40Cr, 42CrMo, etc. Most hammer drill bits on the market adopt a spiral shape in the form of a twist drill. The groove type was originally designed for simple chip removal.
Later, people found that different groove types could not only increase chip removal, but also extend the life of the drill bit. For example, some double-groove drill bits have a chip removal blade in the groove. While clearing the chips, they can also perform secondary chip removal of debris, protect the drill body, improve efficiency, reduce drill head heating, and extend the life of the drill bit.
Threadless dust suction type
In developed countries such as Europe and the United States, the use of impact drills belongs to high-dust working environments and high-risk industries. Drilling efficiency is not the only goal. The key is to accurately drill holes at existing locations and protect workers’ breathing. Therefore, there is a demand for dust-free operations. Under this demand, dust-free drill bits came into being.
The entire body of the dust-free drill bit has no spiral. The hole is opened at the drill bit, and all the dust in the middle hole is sucked away by a vacuum cleaner. However, a vacuum cleaner and a tube are required during the operation. In China, where personal protection and safety are not emphasized, workers close their eyes and hold their breath for a few minutes. This type of dust-free drill is unlikely to have a market in China in the short term.
PART 3: Blade
The head blade is generally made of YG6 or YG8 or higher grade cemented carbide, which is inlaid on the body by brazing. Many manufacturers have also changed the welding process from the original manual welding to automatic welding.
Some manufacturers even started with cutting, cold heading, handling one-time forming, automatic milling grooves, automatic welding, basically all of which have achieved full automation. Bosch’s 7 series drills even use friction welding between the blade and the drill rod. Once again, the life and efficiency of the drill bit are brought to a new height. The conventional needs for electric hammer drill blades can be met by general carbide factories. Common drill blades are single-edged. In order to meet the problems of efficiency and precision, more and more manufacturers and brands have developed multi-edged drills, such as “cross blade”, “herringbone blade”, “multi-edged blade”, etc.
The development history of hammer drills in China
The world’s hammer drill base is in China
This sentence is by no means a false reputation. Although hammer drills are everywhere in China, there are some hammer drill factories above a certain scale in Danyang, Jiangsu, Ningbo, Zhejiang, Shaodong, Hunan, Jiangxi and other places. Eurocut is located in Danyang and currently has 127 employees, covers an area of 1,100 square meters, and has dozens of production equipment. The company has strong scientific and technological strength, advanced technology, excellent production equipment, and strict quality control. The company’s products are produced in accordance with German and American standards. All products are of excellent quality and are highly appreciated on different markets around the world. OEM and ODM can be provided. Our main products are for metal, concrete and wood, such as Hss drill bits, SDs drill bits, Maonry drill bits, wod dhil drill bits, glass and tile drill bits, TcT saw blades, diamond saw blades, oscillating saw blades, bi-metal hole saws, diamond hole saws, TcT hole saws, hammered hollow hole saws and Hss hole saws, etc. In addition, we are working hard to develop new products to meet different needs.
Post time: Jul-03-2024