SK Tool Holder Standards & Taper Specifications

The SK tool holder standard complies with the German Industrial Standard DIN 69871. Machining center spindle tapers are generally divided into two major categories:

1. 7:24 Taper Universal System

2. 1:10 Taper HSK Vacuum System

7:24 Taper Universal Tool Holders
There are five common standards for 7:24 taper tool holders:

• NT (Traditional Type)

• DIN 69871 (German Standard)

• ISO 7388/1 (International Standard)

• MAS BT (Japanese Standard)

• ANSI/ASME (American Standard)
  

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SK Tool Holder Standard (DIN 69871 Classification):
SK refers to the German Industrial Standard DIN 69871, which is further divided into four types:

1. SK Type A: Without center coolant through-hole

2. SK Type AD: With center coolant through-hole

3. SK Type B: With side flange coolant through-hole

4. SK Type AD/B: Features both center and side flange coolant through-holes (side holes are threaded). When using internal coolant through the center, the side holes can be sealed with bolts.