Commonly used materials for drill bits include low-carbon steel, high-carbon steel, high-speed steel, cobalt steel, tungsten carbide, polycrystalline diamond, etc. Surface coatings are black oxide, titanium nitride, titanium aluminum nitride, titanium carbonitride, and diamond powder.
Type:
Machined drills can be divided into two categories, one is flat drills, twist drills, center drills, deep hole drills, and other drilling tools, and the other is reaming drills, countersink drills and other reaming drills. Spiral drill bits are used in construction projects with an outer diameter of 400 to 600 mm and a length between 12 meters and 8 meters. Use flat-bottom drill bits for loose soil layers, use rake bits for miscellaneous fill soil layers, and use barrels for obstacles such as concrete and strips. Type drill.
Twist drill:
Twist drill bits are currently the largest type of output. It includes a cutting point at the tip of a cylindrical shaft with a spiral groove. The groove uses a spiral mechanism to rotate around the axis of rotation through the spiral surface and remove the chips from the hole. The diameter of the torsion bit ranges from 0.002 to 3.5 inches (0.051 to 88.900 mm) [7] and the length to 25.5 inches (650 mm). [8]
Step drill:
The step drill bit is a tapered drill bit with a staircase profile. A drill bit can drill the entire range of holes required on the table surface to speed up the installation of the fixing device. The transition between each diameter is straight to form a countersink. The advantage of this style is that the two diameters have the same flute characteristics, preventing the bit from clogging when drilling in a softer material (such as aluminum); in contrast, a bit with a slip-in collar does not have the same benefit. Most of these bits are customized for each application, which makes them more expensive.
Step drills are most commonly used for softer materials such as plywood, particleboard, drywall, acrylic, and laminate; they can also be used on very thin metal plates, but metal plates often cause premature wear and passivation of the drill.