Best Practices to Strengthen Sheet Metal Design

Design for manufacturability is one of the most important aspects for today’s sheet metal design industry. A sheet metal design ideally is expected to take care of nearly all the features of sheet metal manufacturability. Effective sheet metal design is not the one that eliminates welding; it instead unveils the most cost effective ways to manufacture a part. Best sheet metal design is the one, which exploits the strengths of the welding process and minimizes its weaknesses.

It may be the automotive industry or the aerospace, and even for Building Products and Components Manufacturers, sheet metal is the backbone of the modern industry, and a strong back bone is the inception of a fine product.

The presence of sheet metal work is wide felt nowadays in building construction industry as well in form of, Metal framed windows and doors, structural metal and metal plate work products, ornamental or architectural metal products, Elevators, FACADE and even prefabricated metal buildings in some cases.

The three simple words “sheet metal design” can, and always has a tremendous impact on a company’s bottom line. Innovative, creative, effective and ideal sheet metal design ideas should sprout up in the early phases of product design. It is so because these ideas have the potential to influence the entire project, across manufacturing to product’s end use.

Sheet metal Designer is supposed to be equipped with a clear set of goals and design strategies includingfunction, attachment method, and mechanical properties and manufacturing properties, which are brainstormed before moving into the design cycle. The difference between a flat piece of sheet metal and the body of metal framed windows and doors, or architectural metal products is the power of design. A sheet metal design practice, good or bad, is categorized depending on the previously decided objective.

Based on changing industrial requirements, standard design for manufacturing practices and thorough analysis of results, here are some of the suggestions that may prove really helpful in improving your sheet metal design.

Sheet metal Designer is supposed to be equipped with a clear set of goals and design strategies includingfunction, attachment method, and mechanical properties and manufacturing properties, which are brainstormed before moving into the design cycle. The difference between a flat piece of sheet metal and the body of metal framed windows and doors, or architectural metal products is the power of design. A sheet metal design practice, good or bad, is categorized depending on the previously decided objective.

Rupture Modules

The most important feature of a sheet metal design is the sheet metal’s ability to withstand stress and succeed through the flexure test. The K-factor in the area of bending is visualized depending on the process adopted for bending. Outer surface of the sheet metal witnesses more strain as compared to the inner surface, in the course of bending. Minimum bend radius is the name of the point which results in cracks on the outer surface while bending the sheet metal beyond a point.

So the point that I here would want to put across is that a sheet metal designer should always conceive design ideas with minimum bend radius relating to the thickness of the sheet metal. Now there may be instances where the design would demand increased minimum bend radius, and here the sheet metal would need to undergo various processing such as grounding or polishing.

Holes, Slots and those structured grooves

What is the economical methodology for creating holes in a sheet metal, and everyone would say “Punching”. However; the thing to be considered for such designs is to make provisions for minimum Holes, Slots and structured grooves. This will make the manufacturing a lot easy and will require minimum and error free punching. It will also eliminate the prospects of breakages. Take away here is to make provision for holes where the diameter is equal or more than the sheet metal thickness.

Sheet Metal Bending Radius, keep it minimum

Minimum Bend Radius r = 1*t

The inner bend radius and ductility of a sheet metal is inversely proportionate to each other and is controlled by the tool and process preferred. In course of designing the nature of several grades of sheet metal needs utmost consideration. Moreover; the design for manufacturability software more or less takes all these factors into consideration, proposing an accepted industrial standard that also takes care of the design ideas for designers across.

Welding

Without weighing easily available alternatives, a lot of sheet metal designers include the provision for brackets in their designs.  But they also need to consider:

  • 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 and should be the final goal for all the designers.

Alternatives of Fabrication

Sheet metal often utilizes variegated processes, depending on the end usage. Welding is one such process that may need rigorous grinding. In such scenarios, the designers must leave sufficient room to accommodate this fabrication option.

Minimum Flange Width

The process of creation of a sheet metal part quick and convenient is facilitated by flanges. While conceptualizing a flange, ensure that the flange width is not less than four times the thickness of the sheet metal – in any case. Upon failing to do so, the tool of choice will leave a mark on the sheet metal surface which might invite further challenges.

Die bending; just wipe ‘em out

Of the many processes in sheet metal, edge bending is the one that comes with various advantages, but failing to use it effectively can pose unwanted complexities. While drafting a design with bend forming, provisions for angles less than 90 degree should be made as it would entail less cost and minimal use of complex equipments.

Conclusion

Fondness for details and perfection of sheet metal designers revolve around large amount of design rules and guidelines that ensure manufacturability and assembly. These guidelines at times are hard to remember and time consuming to check as well. Following aforementioned best practices, along with efficient design for manufacturing and assembly software across the equation would ensure an error free end design. Faultless design translates into the optimum utilization of resources at an organization’s disposal. Also, ever evolving industrial practices demand an automated and standardized process to review all the design for manufacturing guidelines.

About the Author: Prahlad Parmar is an Engineering Specialist working at Mechanical 3D Modelling for the past 4 years. He caters critical engineering challenges with ease and performs exhaustive procedures to develop robust, well-engineered and high performance designs. He can always be found in the lab discussing, brainstorming and tweaking designs.