What are the differences between BT toolholder and HSK toolholder

The most commonly used TOOL HOLDER is hsbt.
When the taper of BT toolholder is 7:24 And the rotating speed is about 10000 R / min, the Tool Holder spindle system will not deform obviously. However, when the spindle increases from 10000 R / min to 40000 R / min, the end of the spindle system will deform greatly due to the centrifugal force, and the radial jump increases from 0.2 m to 2.8 M. There will be an obvious gap between the tool holder and the spindle cone hole, which will seriously affect the cutting characteristics of the tool. Therefore, BT toolholder can not be used in high-speed cutting generally

Under high speed, centrifugal force causes deformation of BT toolholder spindle system. The structural form of HSK toolholder cone is different from that of BT toolholder. It is a new type of high-speed taper toolholder, which adopts the double positioning method of cone surface and end face. Under the action of sufficient tension force, HSK toolholder is a new type of high-speed taper toolholder 1: Friction occurs between the taper shank of 10 hollow tool and the 1:10 taper hole of the spindle on the whole cone surface and support plane, providing radial positioning of the closed structure. 1: The German standard of HSK vacuum toolholder is din69873. There are six standards and specifications, namely hsk-a, hsk-b, hsk-c, hsk-d, hsk-e and hsk-f. there are three commonly used ones: hsk-a (automatic tool change with internal cooling), hsk-c (manual tool change with internal cooling) and hsk-e (automatic tool change with internal cooling, high speed type).

HSK TOOLHOLDER

Most of BT and HSK transfer torque through the key, and some toolholders transfer torque through their own shape (such as capto interface). Generally speaking, the toolholder that transmits torque through its own shape is said to be larger and more stable, especially at high speed. The spindle taper hole of machining center is usually divided into two categories, namely general system with taper of 7:24 And HSK vacuum system of 1:10. There are usually five standards and specifications for universal toolholder with taper of 7:24, namely NT (traditional type), DIN 69871 (German standard), IS0 7388 / 1 (International Standard), MAS BT (Japanese standard) and ANSI / ASME (American Standard). The German standard of NT type toolholder is DIN 2080, which is used to tighten the toolholder on the traditional machine tool through the pull rod, which is also known as st in China; the other four toolholders are all tightened by pulling nails at the end of the toolholder on the machining center. At present, DIN 69871 (JT) and MAS BT are the most widely used tool holders in China. The tool holder of DIN 69871 can be installed on the machine tools of DIN 69871 and ANSI / ASME spindle taper hole, while the tool holder of type is07388 / 1 can be installed on the machine tools of DIN 69871, IS0 7388 / 1 and ANSI / ASME spindle taper hole.