MTE D (DOUBLE INSERT) : Double insert thread milling end mills
COOLANT                                            
  DesignationapDdD2L1LShankkgGICATGIREMgiic
  MTE D30-2-W25-21 21.0030.0025.0024.0052.00108.00W0.4006198632 0

Minimum bore should be one-third larger than D (diameter)
All end mills are equipped with a bore for internal coolant