TABLE OF CONTENTS Upset forging is a bulk forming process where the effect of the pressure is on the longitudinal axis of the workpiece.
Commonly used for the production of mass-produced parts such as screws, rivets, head bolts, valve lifters etc. (Figures 4.1, 4.2 and 4.3).
The starting stock is a length of rod cut from round or shaped stock. In many cases, above all in screw and bolt production, production is carried out from wire coils (Figure 4.2). As rolled stock is cheaper than drawn stock, it is used most commonly.
Here, a difference must be made between two criteria:
This sets the limits for the material to be formed (deformability).
Upsetting ? p
Degree of upsetting ? p
? p Degree of upsetting
? p in % = ? h 100
Initial length or length after upset forging, if the permissible deformation is provided
h 0 in mm length before upset forging
h 1 in mm length after upset...
