1. Raw material
Raw material is delivered by trucks from the steel mill stored in one of our warehouses where up to 1,200 tons of steel wire coils can be stored. The materials that make our KNIPEX Cobra® is in one of those coils. To produce KNIPEX pliers roughly 600 tons of high-quality German steel is used per month.
2. Cut to length
First, the machine unrolls the steel wire and brings it into a straight shape. Next, the press cuts the pliers lengthwise, consistently to the same length. The cut pieces of steel are called "Piller" according to the Cronenberger dialect. After the cut, our soon-to-be Cobra® is ready to be forged. The advantage of the initial round shape is a shorter heating time. As a result, the material is less stressed and the forging quality is higher.
3. Forging
At the start of the forging process, each individual "piller" is heated to over 1,000° C. The red-hot steel is shaped between two die halves by the impact force of the forging hammer. The tools that give the glowing steel its shape - the forging dies - are manufactured in-house by KNIPEX. The KNIPEXians in the forge area work under heat and their commitment to this process keeps the blacksmithing tradition of the region alive.
4. Cool down
Before they can be further processed, the recently forged red-hot steel pieces of the pliers need to cool down. They wait with thousands of other forged blanks to enter into the burr press shop.
5. Deburring
Die forging works in such a way that more red-hot steel is introduced into the hollow mold in the die than necessary. When the hammer strikes, the excess material is pushed out through the joint between the two die halves, sealing the gap in the closing die. This creates the high pressures that enable filigree forging (e.g. writings) in forgings. Afterwards, the excess material must be removed in the press shop. To do this, the forging blank is placed in a burr press. The tools, cutting plate and punch are set in place and the deburring (or cutting) process begins.
6. Blasting and calibration
Pliers halves are placed on a conveyor that leads into the blasting drum which is the first surface treatment the pliers will get. In the blasting drum, an abrasive is thrown on the surface to remove the scales that have been created by the previously applied heat. After that, the surface feels smooth, almost like a finished pair of pliers but there is still a long way to go. Next the pliers must go to calibration. In the calibration press, the plier halves are brought into the correct shape by the stamping process.
