What Is a Flat Drill?
A Flat Drill is a cutting tool with a flat tip, unlike a regular drill. Because of its flat shape, it can drill holes on slopes and curves that are difficult to drill with a normal drill. It is also used for boring and drilling cross holes.
Burrs are less likely to appear at the end of the drilled hole, and holes can be drilled flat and straight with less bending. Therefore, it is also suitable for drilling through holes in thin steel plates. In order to prolong the life of the tool, it is necessary to sharpen the cutting edge regularly. Care should be taken because the flat shape of the tip may be lost depending on how it is sharpened.
Although holes can be drilled through a variety of materials, appropriate processing conditions must be selected depending on the hardness of the material.
The diameter and tip angle of the drill used must also be selected appropriately depending on the material to be processed and the shape of the hole.
Uses of Flat Drills
Flat Drills are used for drilling holes on inclined or curved surfaces that are difficult to drill with ordinary drills. Holes can be drilled perpendicular to slopes, and a flat surface can be created by boring to provide guidance during deep hole drilling. Because burrs are unlikely to form at the end of the drilled hole and the hole can be drilled flat and straight, the flat drill is also suitable for through holes in thin steel plates.
Flat Drills are used in a wide range of fields, including automotive parts, electronic parts, and aircraft parts, because of their flexibility in drilling holes through various shapes, including rounded surfaces and intersecting holes.
They have high rigidity and can suppress vibration caused by machining. The ability to handle high-speed machining also provides many advantages, such as improved productivity and machining quality.
Principle of Flat Drill
Flat Drills consist of drilling holes with a flat cutting tool. Because the blade is completely flat, no raised area is created in the center of the hole when boring, allowing pre-processing for deep hole drilling.
In addition, the through-hole prevents softening in areas where the steel is thinner, and burrs at the end of the hole are less likely to appear, enabling efficient drilling of steel plates in a shorter time.
However, the disadvantage is that the entire blade of the flat drill is loaded, so the force to produce chips is weaker than that of a regular drill, and deep holes cannot be drilled. Another factor limiting deep hole drilling is that the gentle torsional angle shape weakens the chip-forming force.
Types of Flat Drills
There are two main types of flat drills: flute drills and spiral drills. Selecting the right type for your application will lead to high-precision drilling and improved productivity.
1. Flute Drill
A Flute Drill is a flat type drill with a completely flat tip. It is mainly used for pre-processing to create a flat surface, such as pre-processing for buckling or deep hole drilling. They are also suitable for mass-production machining, as they can efficiently drill holes through steel plates in a short time. However, when drilling deep holes, chips cannot be produced, so there will be a limit to machining only with flute drills.
2. Spiral Drill
Spiral drills have a spiral tip instead of a flat tip. The angle of the spiral allows chips to be ejected efficiently, making it suitable for deep hole drilling. They also have stronger cutting power and faster machining speed than flute drills, so they can be used for all kinds of machining as well as general drills. However, it can cause a load on the entire cutting tool, a problem unique to Flat Drills.