Be it the aerospace industry or the automotive industry, for the purpose of equestrian or airplane, sheet metal is the backbone of the modern industry. A strong backbone is a desideratum for a fine product.
Sheet metal design plays a vital role in the making of a strong backbone. A designer must have a clear set of goals and design strategies established to ensure that part design is cost effective and can be easily manufactured. Function, attachment method, mechanical properties and manufacturing properties should be mulled over before moving well into the design cycle.The jarring difference between a slice of flat sheet metal and the body of a car is the testimony of the power of design. Depending on the previously decided objective, some would be labeled as good sheet metal design practice while others would be categorized as bad sheet metal design practice.
7 Must-Follow Sheet Metal Design Guidelines
Based on some standard design for manufacturing practices, thorough analysis of results and changing industrial requirements, following are the design guidelines that you should be following to improve your sheet metal design.
1. Modules of rupture
A sheet metal’s ability to withstand stress in a flexure test is an essential facet of sheet metal design. Depending on the process adopted for bending, the K-factor in the area of bending is usually visualized. In the course of bending, the outer surface of the sheet metal witnesses more strain than the inner surface. Bending the sheet metal beyond a point would result in cracks on the outer surface. This point is named as minimum bend radius.
A sheet metal designer should always conceive design ideas with minimum bend radius relating to the thickness of the sheet metal. In case of design intent with increased minimum bend radius, the sheet metal would need to undergo various processing such as polishing or grounding.
2. Structured grooves, hole and slot
Punching is an economical modus operandi for creating holes in a sheet metal. A basic rule of thumb while considering such design is to make provision for a minimum hole, slot or groove size. In such a case, manufacturing becomes easy requiring minimum (and error-free) punching, eliminating the prospects of breakage. An important design tip is to make provision for holes whose diameter is equal or more than the sheet metal thickness.
3. Minimum Sheet Metal Bending Radius
 | This is controlled by the tool and process preferred. The ductility and inner bend radius of a sheet metal is inversely proportionate to each other. The nature of several grades of sheet metal needs to be always taken into consideration in the course of designing. A Design for Manufacturability software often takes all these factors into consideration, proposing an accepted industrial standard accommodating the design idea of a designer. |
4. Fabrication alternatives
Sheet metal, depending on their end use, often make use of variegated processes. Welding is one such process which may require rigorous grinding. In such a case, the designer must leave sufficient room to accommodate this fabrication option.
5. Minimum Flange Width
Flanges make the process of creation of a sheet metal part quick and convenient. In the course of conceptualizing a flange, the following should always be taken into consideration – Flange width must never be less than four times the thickness of the sheet metal. On failing to do so, the tool of choice will leave a mark on the sheet metal surface.
6. Welding
Most sheet metal designers include a provision for brackets in their design, not having weighed the available alternates. Is welding an absolute necessity or cutting the base material would lead to similar end results as well? Can mechanical fasteners help you achieve similar design goals? Efficient and simple design with minimal cost is the final goal for all designers!
7. Wiping die bending
Edge bending is one of the many processes of sheet metal. While this process has many advantages, failing to use this effectively can give rise to unwanted complexities. At the time of drafting a design with bend forming, make provision for angles less than 90 degrees as it would entail less cost and minimal use of complex equipment.
While designers with their penchant for details strive for perfection, it may involve volumes of design rules and guidelines to ensure manufacturability and assembly. These guidelines can be hard to remember and time-consuming to check. Following most of the above mentioned guidelines, the presence of an efficient design for manufacturing and assembly software in the entire equation would ensure an error free end design. Faultless design translates into the optimum utilization of resources at an organization’s disposal.
Further, the ever changing industrial practices demands an automated and standardized process to review all the design for manufacturing guidelines
Learn more about what makes a great sheet metal design. Download the complete DFM eBook
References
I know you can make a lot of things with sheet metal. In fact, I have a couple of things in my garage that use sheet metal. I did not know it was possible to strengthen sheet metal, I will have to see if I can get rid of any unnecessary walk-in on them.
I hadn’t thought about how much thought went into designing and fabricating sheet metal. It must be difficult to try to balance the needs of a certain job with the limitations of the sheet metal’s flexibility. However, as you explained, there are plenty of fabrication alternatives, so I’m sure that there are ways of making every shape possible while still maintaining the strength of the metal. Thanks for the article!
I like your tip to consider fabrication alternatives instead of just going with what you normally use. I especially like how you point out using different methods instead of welding that could produce the same results. Making some of these changes could also help you save money. Thanks for sharing these tips!
The strength of metal is important. It can change the usefulness of the material. I didn’t know that welding could influence the strength of the metal.
This is good info. I have wanted to get into doing this myself for some time and now that I am getting older with a little more time on my hands it is time to start working on my 66 Mustang. Thanks for all the tips and advise!
I like your tip to make provisions for a minimum hole size. Will larger holes make the metal weaker? I also like that this can help prevent breakage during hte manufacturing process. Thanks for sharing theses tips!