Which of the following is the heat treatment process in which iron or steel absorbs carbon liberated when the metal is heated in the process of a carbon bearing material, in order to make the metal harder?

33) The neutral flame is created by supplying the flame with the amount of oxygen which is

34) The process where there is no reduction of material, only a modification in its geometry, is called

35) Which of the following operations involves straightening a curved sheet metal?

36) Which of the following is used for checking the external diameter of a cylindrical object?