All cold headers have a specific method to cut off and measure out a piece of the wire coil. The method of putting the wire inside the cold header and cutting it off often varies depending on the brand needed. Once it is inside the machine, only a cut-off knife will remain. This knife will strike the wire from a defined direction, cutting off a single piece. This process often consists of numerous parts, not mentioning the cut-off knife.

Cold Forming Dies

Since they must withstand heavier loading, dies are very large compared to punches. Dies are found on the stationary part of the cold header. Each die is usually multiple pieces. The working tool is often made in three to four different segments that define the whole working part of the die. Afterwards they are all put under intense pressure into a large, circular curved canister usually named the casing.

The inserted part of the die is put under intense radial pressure with each single blow. They would quickly explode and fail if they lack or do not have some form of support. To solve this problem they are forced hard into the casing. This casing is much larger and is able absorb in and disperse all the pressure building up giving integrity to the die for many parts or cycles.These die casings can be used many times before they need to be changed.

All these dies have a specific sized hole central to the axis of the tool where the part is set. Due to the high pressure that is put on parts, what stops them from shooting out through the die and out through the back of the machine? The knock-out pin system then comes into place. A chain of pins are put at the rear of the die to carry out two functions. Initially during the making portion of the stroke, they stop the part from being driven out through the back of the die. Secondly, at the last phase of the forming stroke, these pins are cast forward driving the part out of the die.

Cold Forming Punches

Punches are found on the moving part of the machine. Compared to dies, punches are smaller because they encounter less pressure during the heading process. Punches also encounter and experience great loading and must be contained in the punch casings.

These punches define the shape or design of the head for the screws. One punch will be the initial blow and the other punch will be the last blow. The punches can also be the support to a pin that pushes the part inside the die. This is usually in cases where the dies are aiding trapped extrusions or recess pins, which aid the backward extrusion to drive recess in parts.

Cold Forming Transfer

This is the last tool system in the transfer mechanism. Cold forming transfer is much simpler when on a single die, two blow machine, because there is only a single transfer necessary, which is the cut off to the die. Nevertheless, once the stepping up process is increased to multiple dies in a multi die header, the transfer mechanism becomes an important component.

The most common tooling pieces used for the transfer are the fingers or grips that hold the parts when they move from one die to the next. The fingers are often custom-made to meet the desired needs for each part. Part geometry is important in transferring a part, as parts can be very heavy. It is possible to upset the head and sometimes a large shoulder, causing the part to droop as it moves out of the die.

The person operating the die has to make sure the transfer is timed right to hold and grab the part before it completely exits the die. However, the transfer does not move the part until it is fully clear of the die. This process requires a lot of practice and experience by the setup technician to master the skill.