Sheet metal is an important component in many of the structures we use every day. It's used in rail tracks, vehicle bodies, and even airplane wings.
But how do metal sheet manufacturers ensure the quality of their products? The answer lies in a robust quality control framework. Here are some of the key steps:.
Design
Sheet metal fabrication is a versatile process used in a number of applications, including electrical, plumbing, automotive, and machine tools. The most common techniques used to create these components include cutting, forming, bending, punching, welding, and finishing. Each step in the production process is crucial to ensure the final product meets quality standards.
Cutting is the first stage in the fabrication of a metal sheet manufacturers. This process involves using specialized scissors or blades to cut through the metal. It can also be done by shearing, in which the metal is forced between two blades with sharp edges. The shearing method is best for straight cuts and can be performed on varying thicknesses of metal. Other methods for cutting metal include punching, in which a metal punch perforates the metal, and laser cutting, which uses a high-powered laser to melt or vaporize the material.
Once the piece has been cut, it is ready for bending. This is one of the most important steps in metal fabrication and can be done on a variety of angles and shapes. It is vital to consider the physics of bending and how it will affect the component. For example, a piece that is bent too much may experience spring back, in which it attempts to return to its original flat structure.
For this reason, it is important to test prototypes. This will help to find any manufacturing issues or design flaws before committing to large-scale production. The testing phase will also allow engineers to evaluate the performance of the component in real-world environments, which can be difficult to replicate with computer simulations.
Fabrication
Sheet metal fabrication is a highly-automated process that ensures tight tolerances and a high level of accuracy. It is also highly flexible, allowing manufacturers to adjust production processes quickly and easily as the project evolves. This flexibility makes metal fabrication a great choice for projects with changing requirements, such as the design of prototypes.
The fabrication process for metal sheet manufacturers is a complex one that involves cutting, bending, punching, stamping, and forming.
Each process requires a specific technique, so it is important to understand the different options before selecting a manufacturer. For example, shearing is a cutting method that separates flat metal materials by applying force. This is a good option for high-volume applications and for cutting soft materials like aluminum, mild steel, and brass. However, it is not ideal for curved surfaces or materials that require a clean finish.
Other forming methods include roll bending, which uses a hydraulic press and three rollers to create curved shapes. It is used for components like tubes and cones. Another forming method is rotary bending, which is a fast and efficient method for creating U-shaped structures. It requires a wipe die to set the radius of the bend.
For bending, it is best to use thinner metals for the most reliable results. Thicker metals may produce microscopic cracks that can cause the final product to fail. It is also best to avoid bending metals that are too stiff.
Testing
Sheet metal fabrications are subject to strict quality control standards. This ensures that they will be produced to the exact specifications of their design and will function as expected. While the quality of a sheet metal part is largely determined by the manufacturing process, regular testing and inspection will verify that the resulting product meets high quality standards.
During the production of a custom metal staircase or bulk storage solution, for example, careful inspection is critical to ensure that each step in the process is executed accurately and without error. This means that the dimensions of the part must be accurate, no dust or pollution has been introduced to the surface and the welded joints have been securely bonded.
In addition to dimensional verification, the quality of a piece can be assessed using a variety of tests. Testing types vary depending on what the manufacturer is looking to measure about a particular material. Tensile strength tests, for instance, test the bending or stretching limit of a sheet metal. Fatigue testing measures cyclical material failure, and hardness tests measure resistance to permanent deformity.
Other common testing methods include shearing and hole expansion. For the former, a sample is sheared and then widened. The ratio of the expanded diameter to the original measurement is then measured and recorded as a characteristic value called the hole expansion ratio.
Inspection
As with all fabricated metal products, inspections are an integral part of the manufacturing process. These inspections take place in receiving, at various stages throughout production, and prior to packaging and shipping. The schedule and method of inspection should be agreed upon ahead of time and put in writing. For example, if a specific surface finish is required on your finished metal parts then an R&R (Reject and Rework) study might be employed to ensure that all inspectors are aware of the requirements.
Typical inspection tools such as low cost calipers, tapes and protractors are insufficient for sheet metal work because they are too slow and prone to operator error. This can lead to faulty 2D and 3D parts being sent further up the production line. For example bending a part on a press brake is extremely reliant on operator skill and errors in bending radius can be caused by incorrect tooling or even the kerf of the edge profile of the metal sheet manufacturers which are difficult to spot with simple inspection equipment.
While coordinate measuring machines (CMMs) are commonly used in quality assurance, they are expensive to buy and run and have poor accuracy for inspecting 2D and 3D shapes which are defined by their edges. Alternatively, portable 3D laser scanners such as FARO’s i-Series eliminate this measurement bottleneck by capturing thousands of data points on a part in seconds, and then comparing them to the design for any extra or missing features.