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Sheet metal bending accuracy problem: 5 Reasons & Solutions

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The commonly used metal materials in the hardware parts we often use are stainless steel, copper, aluminum, zinc alloy, magnesium alloy, steel, iron, etc.

Sheet metal fabrication process
Sheet metal fabrication process

Hardware products are often divided into cold processing and hot processing according to different processing methods. Different types of hardware forming methods are also different. Cold processing, such as sheet metal materials, is mainly through cold stamping, bending, rolling, deep drawing, and other processes. forming. Thermal processing, such as casting parts, is mainly made by melting metal raw materials into liquid and casting them with molds.

It is generally believed that all sheet metal materials with uniform thickness are collectively referred to as sheet metal. Commonly used sheet metal materials are stainless steel, galvanized steel, tinplate, copper, aluminum, iron, etc.

CNC bending machine

The CNC bending machine affects the bending accuracy, the stop position of the slider affects the bending angle, and the position of the back gauge affects the bending size.

Solution: These need better CNC bending machines to solve.


The experience and techniques of the operator affect the bending accuracy. When the worker pushes the stopper, the force is too large or too small, resulting in a gap in the positioning or the bending of the sheet, which affects the bending dimensional accuracy; the worker’s bending speed is not synchronized with the speed of the machine tool, which will cause bending. The bending angle is too large or too small.

Solution: Bending workers should be skilled and experienced, and do not change operators frequently.

Bending factor

The bending coefficient affects the accuracy of the bending dimension, and the bending dimension of the sheet metal has been determined when the unfolded drawing is made. In the unfolded view, the bend factor is a key factor in determining the size of the bend. The inaccurate calculation of the unfolded drawing directly affects the dimensional accuracy of sheet metal bending.

Solution: Sheet metal technicians are familiar with the principle of sheet metal unfolding, and can accurately determine the accurate bending coefficient according to theory and practice.

Material quality

The material quality affects the bending dimensional accuracy, and the material thickness directly affects the bending coefficient, which affects the bending accuracy.

Solution: Purchase from good steel mills and strengthen thickness and dimension inspection.

Mechanical properties

Different mechanical properties of materials can also affect the bending dimensional accuracy, such as steel plates being soft or hard, resulting in different stretches.

Solution: Try to use the same batch of steel plates to make a sheet metal product, and check the bending coefficient of the same batch of steel plates.