What Does ‘Drop-Forged’ Mean?
What Does 'Drop-Forged' Mean?
The strength of steel is improved by the drop-forge process. Potential stress areas are strengthened due to the alignment of the grain under pressure. This cannot be achieved via maching, fabrication nor casting methods.
Drop Forged Steels
A hammer is raised and then “dropped” onto the workpiece to deform it into the required shape/form. This can be done either by hand or machine.
Moulds called ‘dies’ are used. These dies are made from hot-working tool steels with high hardness and wearability factors.
There are two types of drop forging:
Open-die drop forging
Closed-die drop forging
Open-Die Drop Forging
The open-die drop forge process shapes the tools under extreme pressure using heavy hammers which ‘drop’ onto the steel, shaping it, allowing the natural grain structure of the steel to ‘flow’ and form the desired shape.
Open-die drop forging does not fully encase the workpiece, whereas closed-die drop forging does.
Closed-Die Drop Forging
The process for closed-die forging is the same except instead of hammers, a press is used to force the moulding dies together.
Drop forged alloy steel has high strength. Spanners made from drop forged alloy steel which have been heat-treated, for example, are of high quality and usually last many years even with a lot of use.
