Types Of Drop Hammers and their Capacity

Three types of drop hammers are used in making drop forgings. 

They are 

• Board or gravity hammer, 
• Air-lift hammer, and
• Power drop hammer or what is usually called steam hammer. 

The working principle in each of the two types is almost similar to that of the forging hammers. The anvil block of a forging hammer is built on a foundation separate from the frame, while the anvil of a drop forging hammer is attached to the frames to permit accurate alignment of  the upper and lower dies.

CAPACITY OF DROP HAMMERS :

The same factor as explained for forging hammers determines the energy and force delivered by a drop hammer. Direct calculations to determine what capacity is needed is quite complex. An empirical rule of thumb is that a gravity drop hammer's rated size in kilograms should be equal to the product of the area of the final die-impression and the flash times 20 to 37, depending on the shape and type of a material. A double-acting steam drop hammer may have a rating of 6 of that of a gravity drop hammer but be suited for the same job.