The knife handle of the different milling machines is also different. Universal milling machines generally use the knife handle cone taper of 7:24.
First, the taper 7:24 general handle holders usually have five kinds of standards and specifications:
NT (traditional) (referred to as NT or ST)
DIN 69871 (German standard) (referred to as JT, DIN, DAT or DV)
IS0 7388/1 (International Standard) (referred to as IV or IT)
MAS BT (Japanese Standard) (BT)
ANSI / ASME (American Standard) (CAT)
NT-type tool holder German standard for the DIN 2080, is a universal milling machine through the rod will pull the knife handle, the domestic also known as ST;
The other four kinds of shanks are in the processing center through the handle of the tail of the pull the knife to tighten the handle. At present, the largest domestic use is DIN 69871 type (JT) and MAS BT type two kinds of knife handle. DIN type 69871 handle can be installed in the DIN type 69871 and ANSI/ASME taper of spindle of milling machines, IS0 7388/1 handle can be installed in the DIN type 69871, IS0 7388/1 and ANSI/ASME on a machine tool spindle taper. So in general terms, the IS0 7388/1 is the best.
★ Pull nails have three key parameters: θ angle, length l and thread G.
There are several cases about the angle of the shank:
1, MAS BT (Japanese standard) knife handle pull angle θ has 45 degrees, 60 degrees and 90 degrees of points, commonly used is 45 degrees and 60 degrees;
2, DIN 69871 knife handle nails (usually referred to as DIN 69872 – 40/50) θ angle is only a kind of 75 degrees;
3, IS0 7388/1 knife handle pull nails (usually called IS0 7388/2 – 40/50) θ angle of 45 degrees and 75 degrees;
4, ANSI/ASME (American Standard) knife handle pull angle θ 45 degrees, 60 degrees and 90 degrees.
For the thread G of the tool holder, except for ANSI / ASME (American standard), there are British thread standards for the handle screw, and the other three are made of metric threads. The 40 # handle is usually used M16 thread, 50 # knife Handle nails are usually used with M24 threads.
7:24 of the knife handle are:
JT series shank (ISO, German DIN standard, China GB standard)
BT series handle (Japan MAS standard)
JT-WA series handle (Germany VDI standard)
JT-U series shank (American ANSI standard)
CAT Series Tool Holder (American ANSI Standard – Caterpillar)
ST series handle (China GB standard)
SK series handle (German DIN standard)
NT is just our popular name, there are metric, imperial division of the points.General Japan NT is divided into NT (U) and NT (m). DIN2080 is metric. China’s ST standard is in accordance with DIN2080 standard, so ST that NT (m) and DIN2080 can be common.
JT standard number is: GB10944. It is made with reference to DIN69871 / 1, and ISO7388 / 2 is common. DIN69871 general German abbreviation: SK. Three standard parameters are generic. So some people called JT, ISO, DIN, SK. As for DV, DAT those names, it is some companies take the name, not standardized.
Only by clearly understanding these specifications and standards, we can for the milling machine or universal milling machine to choose the right knife handle.