7: Universal tool shank with 24 taper
There are usually five different standards and specifications for universal tool holders with a taper of 7:24, namely, NT, DIN 69871, IS0 7388 / 1, masbt and ANSI / ASME. At present, the most commonly used handle models in China are DIN 69871 and masbt.
The German standard of NT type tool holder is di2080 and the international standard is ISO 2583. It is characterized by the need to manually mount the tool. On the traditional machine tool, the tool holder is tensioned by the pull rod, and the tool cannot be loaded by the manipulator of the machine tool. While the other four types are used to tighten the tool shank by the pull pin at the end of the tool shank on the machining center.
Din 69871 is divided into two types, namely DIN 69871a / AD and DIN 69871 B. the former has the function of central internal cooling, while the latter has the function of flange internal cooling. There is no difference in other aspects.
The mounting dimension of ISO 7388 / 1 tool holder is the same as that of DIN 69871, but the D4 value of the former is smaller than that of the latter. Therefore, ISO 7388 / 1 tool holder has the best versatility and can be installed on DIN 69871 taper hole machine tool. However, if the din 69871 tool holder is installed on the ISO 7388 / 1 taper hole machine tool, interference may occur.
Masbt is a Japanese standard, and its installation size is completely different from the first three, so it cannot be replaced. This type of tool holder adopts symmetrical structure, which makes it have higher high-speed stability compared with other three types of tool holders.
ANSI b5.50 complies with the American Standard. Although its installation dimension is similar to DIN 69871 and IS0 7388 / 1, it cannot be installed on these two kinds of machine tools due to the lack of a wedge notch. However, DIN 69871 and IS0 7388 / 1 tool holders can be installed on ANSI b5.50 machine tools.
1: 10 taper HSK vacuum tool holder
The German standard for HSK vacuum tool holder with taper of 1:10 is din69873. When it comes into contact with the spindle of the machine tool, not only does the 1:10 taper of the tool holder contact with the 1:10 taper of the spindle hole, but also the flange surface of the tool holder can be in close contact with the spindle surface by elastic deformation. Compared with the 7:24 tool holder, this double-sided contact system has certain advantages in high-speed machining, connection rigidity and coincidence accuracy. There are six different standards and specifications for HSK vacuum tool holders, namely hsk-a, hsk-b, hsk-c, hsk-d, hsk-e and hsk-f. Among them, hsk-a, hsk-e and hsk-f are most commonly used in the automatic tool changing system of machining centers.
The difference between these two types is mainly reflected in two aspects: on the one hand, hsk-a is equipped with a transmission groove, while hsk-e is not. The result of this difference is that the torque transmitted by hsk-a is greater than that of hsk-e, which can undertake some heavy cutting tasks, while the latter can only perform some light cutting. On the other hand, the hsk-a tool handle is also equipped with manual fixing holes, directional grooves, etc., which will have a certain impact on the balance. Hsk-e is more suitable for high-speed machining without these devices.
The structures of hsk-e and hsk-f are completely the same. The difference lies in the taper size. That is to say, for hsk-e and hsk-f tool shanks with the same flange diameter, the taper of hsk-f is always one size smaller than that of hsk-e. Therefore, the former main shaft bearing is smaller and the rotation speed will be faster.
