OLICNC TAKING ABOUT BASIC KNOWLEDGE OF TOOL HOLDERS

1. Universal tool holder with 7:24 taper Universal tool holders with a taper of 7:24 usually have five standard specifications, namely NT (traditional), DIN 69871 (German standard), IS07388/1 (international standard), MAS BT (Japanese standard) and ANSI/ASME ( American standard).
   The NT type tool holder, the German standard is DIN 2080, is used to tighten the tool holder on a traditional machine tool through a pull rod, which is also called ST in China; the other four tool holders are all fixed on the machining center through the pull stud at the end of the tool holder. The handle is tightened.
   At present, the two most used tool holders in China are DIN 69871 type (ie JT) and MAS BT type. Holders of type DIN 69871 can be mounted on machine tools with type DIN 69871 and ANSI/ASME tapers, and holders of type IS0 7388/1 can be mounted on type DIN 69871, ISO 7388/1 and ANSI/ASME tapers. machine tools, so in terms of versatility, ISO 7388/1 type holders are the best.

(1) DIN 2080 type (abbreviated as NT or ST)
DIN 2080 type is the German standard, that is, the international standard ISO 2583. It is what we usually call the NT type tool holder. The tool cannot be loaded by the manipulator of the machine tool but manually loaded.

(2) DIN 69871 type (referred to as JT, DIN, DAT or DV, SK)
DIN 69871 type is divided into two types, namely DIN 69871 A/AD type and DIN 69871 AD+B type, the former is central inner cooling, the latter is central inner cooling + flange inner cooling, the latest machine tools will be used more often, Other dimensions are the same.

(3) ISO 7388/1 type (referred to as IV or IT)
The shank mounting dimension is no different from DIN 69871 type, but since the D4 value of ISO 7388/1 type shank is smaller than that of DIN 69871 type shank, the ISO 7388/1 type shank is installed in the DIN 69871 type taper hole There is no problem on the machine of the type DIN 69871, but there is a possibility of interference when the DIN 69871 type tool holder is installed on the type of ISO 7388/1 machine.

(4) MAS BT type (abbreviated as BT)
Type BT is a Japanese standard, and its installation dimensions are completely different from those of DIN 69871, ISO 7388/1 and ANSI, and cannot be used interchangeably. The symmetrical structure of the BT-type tool holder makes it more stable at high speed than the other three tool holders.

Since the MAS BT type tool holder only uses the taper surface and the machine tool spindle to connect the shaft, in order to meet the modern requirements of higher precision and high speed, Japan has newly introduced the BT PLUS type tool holder, referred to as the BBT type. The BBT type tool holder combines some of HSK’s Features, the flange surface is in contact with the machine tool spindle, and the rigidity is better. The BBT type tool holder can be installed on the MAS BT type machine tool spindle, otherwise, it cannot, and the tool drop accident is prone to occur.

(5) ANSI B5.50 type (abbreviated as CAT)
ANSI B5.50 type is the American standard, the installation size is similar to DIN 69871, ISO 7388/1, but because of one less wedge notch, so ANSI B5.50 type shank can not be installed on DIN69871 and ISO 7388/1 machine tools, but DIN 69871 and ISO 7388/1 holders can be mounted on ANSI B5.50 type machines.

2. 1:10 HSK vacuum tool holder

The German standard for HSK vacuum tool holders is DIN69873. There are six standard specifications, namely HSK-A, HSK-B, HSK-C, HSK-D, HSK-E and HSK-F. There are three commonly used: HSK-A (automatic tool change with internal coolant), HSK-C (manual tool change with internal coolant) and HSK-E (automatic tool change with internal coolant, high speed type).

The biggest difference between Type A and Type E is:

1. Type A has a transmission groove and type E does not. Therefore, the A-type transmission torque is relatively large, and some heavy cutting can be carried out relatively. The torque transmitted by the E-type is relatively small, and only some light cutting can be performed.
2. In addition to the transmission groove, there are also manual fixing holes and direction grooves on the A-type tool handle, so the balance is relatively poor. The E type does not, so the E type is more suitable for high-speed machining.

The mechanism of E-type and F-type is exactly the same, and their differences are:

The E-type and F-type shanks of the same name (such as E63 and F63), the taper of the F-type shank is one size smaller. That is to say, the flange diameters of E63 and F63 are both φ63, but the taper size of F63 is only the same as that of E50. So compared to the E63, the F63 will have a faster speed (smaller spindle bearing).

3. Different connection methods The 7:24 universal tool holder is connected by the contact and positioning of the 7:24 tapered surface of the tool holder and the 7:24 tapered surface of the machine tool spindle hole, which has limitations in high-speed machining, connection rigidity and coincidence accuracy.
   The HSK vacuum tool holder relies on the elastic deformation of the tool holder, not only the 1:10 tapered surface of the tool holder and the 1:10 tapered surface of the machine tool spindle hole, but also the flange surface of the tool holder and the spindle surface are in close contact. The surface contact system is superior to the 7:24 universal tool holder in high-speed machining, connection rigidity and coincidence accuracy.

Four, pull nails

Pull studs have three key parameters: θ angle, length L and thread G

Regarding the θ angle of the handle pull stud, there are the following situations:

1. The θ angle of MAS BT (Japanese standard) shank pull stud is divided into 45°, 60° and 90°, and the commonly used ones are 45° and 60°; the θ angle of BBT shank pull stud is 15°;
2. DIN 69871 handle pull stud (usually called DIN 69872-40/50) has only one θ angle of 75°;
3. ISO 7388/1 shank pull stud (usually called ISO 7388/2-40/50) θ angle is divided into 45° and 75°;
4. The θ angle of ANSI/ASME (American Standard) shank pull stud is divided into 45°, 60° and 90°;
5. According to the needs of the machine tool, the pull stud can be divided into without inner cooling (commonly used), with central inner cooling and central inner cooling with O-RING sealing ring.

Regarding the thread G of the shank pull stud, except for the ANSI/ASME (American Standard) shank pull stud, which has an inch thread standard, the other three use metric threads. The 40# shank pull stud usually uses M16 thread, 50# knife Shank pull studs usually use M24 thread
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