The lower part of the handle is the tool holder part, which is used to clamp the tool. The type of taper handle: It depends on the way the tool holder is connected to the machine tool. The choice of the connection method between the tool holder and the machine tool spindle mainly considers the way of tool change, the source of clamping force) and the speed, etc. There are two most commonly used types, namely the steep taper handle sksk type or bt type with a taper of 7:24 or 7:24 universal type. This type of tool holder has a larger taper of 7:24 and is the most commonly used tool holder. It can withstand higher speeds and higher torques and is mostly used in automatic tool changing machines. Its taper handle is directly installed in the tapered hole of the machine tool spindle. There is a connecting bolt on the top of the tool holder to pull it upward to pull the tool holder into the machine tool spindle. At the same time, it is mainly clamped by the friction between the tool holder and the machine tool spindle wall.
There are two types of specialized tapping tool holders: one is a spring tapping tool holder, which is somewhat similar to an ER tool holder, but is elastic. The second is a telescopic tapping tool holder, and the other is to directly install the tap on the ER tool holder to tap threads. For typical workpieces with large batches and complex processing, composite cutting tools should be used as much as possible. Although composite cutting tools and tool holders are relatively expensive, the use of composite cutting tools on machining centers can combine multiple processes into one process and be completed by one tool, which is beneficial to reducing processing time and the number of tool changes, and significantly improving production. efficiency. For some special parts, specially designed composite tool holders can also be considered.