What is Stretcher Leveling?
Stretcher Leveling is the process of removing or breaking the memory of the coil to create “dead flat” or “laser flat” material.
The primary function of this line is to transition a master coil to “laser flat” sheets. The first step is to flatten and reduce the crossbow. A crossbow is a curvature in the transverse (horizontal) direction. There are three E- Drive Levelers that hydraulically work the material to reduce crossbow and wave.
Imagine stretching a rubber band until it turns white and cannot be stretched anymore.
Next, the material travels to the stretcher. The line grabs forty feet of material at a time and applies an impressive 2 million pounds of pressure. This process stretches the material past its yield point, breaking the material of its internal stress. From here, the material heads to the shear, where it is cut into sheets and packaged to your customization.
What is Temper Passing?
Temper passing is the process of compressing steel between two rollers. This squeezes out the internal stress, leaving the material flat, elongated, and work hardened.
What are the main differences between Stretcher Leveling VS Temper Passing?
Temper Passing used to be the popular way to reduce stress and create “dead flat” material; however, Stretcher Leveling offers solutions and benefits temper passing can’t.
Price: Temper Passing is often more expensive due to the amount of manual labor required.
Decreased Thickness: Due to the amount of compression placed on temper pass steel, the material thickness can decrease up to 3%.
Elimination of Spring Back: Material that hasn’t had all internal stress eliminated can hurt your bottom line and fabrication equipment.
Bowed material or spring back can remove the head of a laser, costing you repair costs and downtime.