7: Universal tool handle 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 tool handles in China are DIN 69871 and masbt.
The German standard of NT type tool holder is di2080 and the international standard is ISO 2583. Its feature is that it needs to install the tool manually. On the traditional machine tool, the tool holder is tightened through the pull rod, and the tool cannot be installed by the manipulator of the machine tool. The other four types are tightened by the pull nails at the end of the tool handle on the machining center.
Din 69871 is divided into two types: 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, and there is no difference in other aspects.
The installation dimension of ISO 7388/1 tool holder is the same as that of DIN 69871, but the D4 value of the former is less 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, but conversely, installing DIN 69871 tool holder on ISO 7388/1 taper hole machine tool may cause interference.
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 handle adopts symmetrical structure, which makes it have higher high-speed stability than the other three tool handles.
ANSI b5.50 complies with American standards. Although its installation size is similar to DIN 69871 and IS0 7388/1, it cannot be installed on these two machine tools due to the lack of a wedge notch, but DIN 69871 and IS0 7388/1 tool handles can be installed on ANSI b5.50 machine tools.
1: 10 taper HSK vacuum tool holder
HSK vacuum tool holder with a taper of 1:10 complies with the German standard din69873. When it is in contact with the spindle of the machine tool, it is not only the 1:10 conical surface of the tool holder in contact with the 1:10 conical surface of the spindle hole, but also the flange surface of the tool holder can be in close contact with the spindle surface by means of elastic deformation. This double-sided contact system has certain advantages in high-speed machining, connection rigidity and coincidence accuracy compared with the 7:24 tool holder. 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, three types of hsk-a, hsk-e and hsk-f are most commonly used in the automatic tool change 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 transmission grooves, while hsk-e does 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 carry out some light cutting. On the other hand, hsk-a tool handle is also equipped with manual fixing holes, direction grooves, etc., which will have a certain impact on the balance. Hsk-e model is more suitable for high-speed machining without these devices.
The structure of hsk-e type and hsk-f type is completely the same, and the difference lies in the taper size, that is, hsk-e type and hsk-f type tool handles with the same flange diameter, and the hsk-f type cone is always one size smaller than hsk-e type. Therefore, the former spindle bearing is smaller and the speed will be faster.