Drill selection method
Drill selection method:
1. Reasonable selection of cemented carbide drill bits
In the past, it has been thought that drilling must be carried out at lower feed rates and cutting speeds, a view that was once correct under the processing conditions of a conventional drill bit. Today, with the advent of carbide drills, the concept of drilling has changed. In fact, by properly selecting the right carbide drill, the drilling productivity can be greatly improved and the processing cost per hole can be reduced.
2. Basic types of carbide drills
There are four basic types of carbide drills to choose from: solid carbide drills, carbide indexable inserts, welded carbide drills and replaceable carbide crown drills. Each drill has the advantage of being suitable for a particular processing condition.
3. Solid carbide drill bit
Solid carbide drills are suitable for use in advanced machining centers. This drill is made of fine-grained carbide material. It is also coated with TiAlN for extended service life. The specially designed geometric edge shape makes the drill bit have self-centering function and has good performance in drilling most workpiece materials. Chip control and chip removal performance. The self-centering function of the drill bit and the tightly controlled manufacturing accuracy ensure the drilling quality of the hole and no further finishing is required after drilling.
4. Carbide indexable insert bit
Drills with carbide indexable inserts have a wide range of machining depths from 2D to 5D (D is the bore) for lathes and other rotary machines.
5. Welded carbide drill bits
Welded carbide drills are made by firmly welding a carbide crown on a steel drill body. This kind of drill adopts self-centering geometry and has small cutting force. It can achieve good chip control for most workpiece materials. The finished hole has good surface finish, high dimensional accuracy and positioning accuracy, and no need for subsequent precision. machining. The drill is internally cooled and can be used in machining centers, CNC lathes or other high-rigidity, high-speed machines.
6. Replaceable carbide crown bit
The replaceable carbide crown bit is a new generation of drilling tools developed in recent years. It is a combination of a steel drill body and a replaceable solid carbide crown. Compared with a welded carbide drill, the machining accuracy is comparable. However, since the crown can be replaced, the machining cost can be reduced. Improve drilling productivity. This drill bit achieves precise hole size increments and self-centering, so the hole machining accuracy is high.