Basic knowledge sharing of toolholder

Taper classification of toolholder
There are usually five standards and specifications for universal toolholder with taper of 7:24, namely NT (DIN 2080 / ISO 2583 type), DIN 69871 (German standard), IS0 7388 / 1 (International Standard), MAS BT (Japanese standard) and ANSI / ASME (American Standard).

1) Din 2080 (NT or ST for short)

Din 2080 is a German standard, that is, the international standard ISO 2583. It is the NT type TOOL HOLDER that we usually call NT type. It is used to tighten the tool handle on the traditional machine tool through the pull rod. It is also known as st in China. It can not be loaded by the manipulator of the machine tool, but by hand.

2) Din 69871 (JT, DIN, dat or DV for short)

There are two types of DIN 69871, namely DIN 69871 A / AD and DIN 69871 B,
The former is the center inner cooling, the latter is the flange inner cooling, other dimensions are the same.

3) ISO 7388 / 1 (IV or it for short)

There is no difference between the installation dimension of the Tool Holder and DIN 69871 type, but because of the ISO 7388 / 1 type
The D4 value of the tool holder is less than that of the din 69871 type tool holder, so the ISO 7388 / 1 tool holder is replaced
It is no problem to install it on the machine tool with DIN 69871 taper hole, but it is not a problem to install DIN 69871 type cutter
Interference may occur when the handle is installed on the ISO 7388 / 1 machine tool.

4) MAS BT type

BT type is a Japanese standard, and its installation dimensions are consistent with DIN 69871, IS0 7388 / 1 and ANSI
It's all different. It can't be changed. The symmetrical structure of BT type toolholder makes it better than other three kinds of toolholder in high speed stability.

5) ANSI b5.50 (cat for short)

ANSI b5.50 is an American Standard. Its installation dimension is similar to DIN 69871 and IS0 7388 / 1. However, due to the lack of a wedge notch, ANSI b5.50 toolholder cannot be installed on din69871 and IS0 7388 / 1 machine tools, but DIN 69871 and IS0 7388 / 1 toolholders can be installed on ANSI b5.50 machine tools.