Tool clamping

The importance of tool clamping technology

As the link between machine and tool, tool clamping technology creates optimum conditions for ensuring precision, efficiency and process reliability in the field of machining. 
In recent years, the number of variants has increased considerably, and precision toolholders in particular are gaining in importance. These developments result from the increasing quality and performance of machine tools, which not only increase the demands on process reliability, but also in terms of tool life. In this context, quick-change systems and modular construction kits offer a wide range of possibilities to enable quick changeover of clamping devices and to make production more flexible.

The various interfaces between machine and tool

In practice, machine and spindle are often connected via a taper shank. In this case, standardized interfaces are essential for accommodating the toolholders in the machine.

Morse taper (MK)

The Morse taper represents the oldest interface and is standardized according to DIN 228. Mostly this interface is used in hand-operated drilling machines, where the torque transmission takes place by means of static friction in the taper. Nowadays, this interface is less common. In machining centers and lathes, steep taper (SK) and hollow shank taper (HSK) are mainly used today.

Steep taper (SK)

The SK interface is standardized according to DIN 69871 and 2080 and is still a practical solution today despite the increasing use of the HSK interface. Due to the relatively large taper angle, the steep taper is not self-locking. It centers well during tool changes and is easy to release. With this interface, the tool must be pulled continuously into the holder. The force transmission is frictionally engaged via the taper. Reliable torque transmission is ensured via grooves in which sliding blocks on the work spindle engage, thus enabling a form fit. A disadvantage of the SK interface is that at high speeds the forces that occur increase significantly, since centrifugal or centrifugal forces expand the taper sleeve of the main spindle. As a result, the tool is pulled further in during operation and jams at standstill. Thus, the SK interface reaches its limits at high speeds, which is why the HSK interface was developed.

Hollow shank taper (HSK)

The HSK interface is standardized according to DIN 69893 and can be regarded as a further development of the steep taper. Compared to the SK interface, the hollow shank taper is about 50% lighter and 30% smaller, which should not only simplify but also speed up the tool change. A small taper angle causes the HSK interface to rest against the face of the work spindle, resulting in high rigidity and changeover accuracy in the axial direction. The hollow shank taper is particularly well suited for high rotational frequencies, as the high forces push the clamping elements outwards and increase the clamping force on the taper surface.

Buy tool clamping technology at PACH Systems

In the field of tool clamping technology, we offer you various OTT-JAKOB and Ortlieb Präzisionssysteme GmbH & Co. KG clamping technology products that are required for a complete tool clamping unit. Therefore our product range is not only limited to HSK tool gripper or SK collets. You will also find Rotary Unions, unclamping units, clamping chucks and more.