The main milling operations are as follows :

 Milling operations :-

1) Plain or slab milling :-  It is an operation of producing flat or horizontal surface parallel to the axis of the cutter. 

2) Face milling :- It is an operation of producing flat surface at right angle to the axis of the rotation of cutter. 

3) Angular or bevel milling :- It is an operation of producing flat surface at an angle to the axis of the cutter. 

4) Side milling :-  It is an operation of producing vertical flat surface on the side face of a job by using a side milling cutter. 

5) End milling :- It is an operation of producing flat surfaces either horizontal, vertical or at an angle by using an end milling cutter. 

6) Form milling :- It is an operation of producing surfaces of irregular shape. The cutter (known as form or profile cutter)  has the same profile corresponding to the surface to be produced. 

7) Gang milling :- It is an operation of producing many surfaces of a wirkpiece simultaneously by feeding the table against a number of required cutters. 

8) Saw milling :- It is an operation of producing narrow slots or grooves on a workforce. 

9) Helical or spiral milling :- It is an operation of producing grooves around the periphery of a cylindrical or conical workpiece. 

Up Milling and Down Milling :-  The process of removing metal by a cutter which is rotated against the direction of travel of the workpiece is called up - milling. It is also called conventional milling. In up milling, the chip thickness is maximum at the beginning of the cut and maximum at the end of cut. The cutting force varies from zero to maximum. 

      The process of removing metal by a cutter which is rotated in the same direction of travel of the workpiece is called down milling .It is also called climb milling. In down milling, the chip thickness is maximum at the beginning of the cut and minimum at the end of cut. The cutting force varies from maximum to zero.