The Right Metalforming Process for Project Success

Choosing the proper metalforming process for a project is an art as well as a science. You have to account for desired aesthetic, cost, part function, part volume, time to manufacture, and much more. Finding the right turnkey metal part and assembly manufacturer often makes the difference when it comes to delivering a project on time and on budget.

While the best metalforming method depends on your application, the right metal manufacturing partner with in-house engineers will work with your team to determine the ideal forming process based on your industry’s requirements. Learn more about common metalforming processes below and key considerations when selecting each method.

Determining Your Metal Forming Process

A full-service manufacturer will offer multiple metalforming processes under one roof, including an initial design, engineering, and quality control consultation to ensure your part design will function exactly as intended. Your manufacturing partner will help you select the appropriate forming process based on potential impact on your overall project costs, lead times, and quality

Roll Forming

Roll forming turns sheet metal into pipes and tubes. The flat sheet is run through a series of roller dies until it begins to curve; the sheet can then be closed to form a tubular structure. Roll forming can only be used to create symmetric shapes, so it’s not the ideal choice for more complex asymmetric parts. 

However, this metalforming process is ideal for OEMs looking to economically produce high volumes of close tolerance parts with a broad range of geometries. A turnkey metal part and assembly manufacturer can provide advanced inline sweep-rolling and arc-rolling capabilities to create complex, aesthetically-superior parts, from oven window and refrigeration components to automotive cargo shade and bicycle frame parts.

Roll-forming benefits include:

  • Reduced waste, secondary operations, and labor costs
  • Elimination of higher cost plastics and extruded parts
  • Increased options, including compatibility with both ferrous and non-ferrous metals and the ability to fabricate finished or painted parts

Your metal manufacturing partner may also suggest an inline roll-forming process to minimize part handling and reduce customer costs.

Tubular Stamping

Tubular stamping is a relatively new, cost-effective process that turns flat metal stock into a tubular shape through a series of stamping operations. The blank is shaped around a die step-by-step until it forms a tubular shape; another tool is then used to complete the roll. Manufacturers use tubular stamping to create complex asymmetric shapes, which differentiates this process from roll forming. 

Advantages of this metalforming process include:

  • Greater strength-to-weight ratios
  • More design feature options, such hemmed or coined edges, without incurring additional machining costs
  • Up to 30% lower manufacturing costs than screw-machined parts, die casting, and aluminum extrusions


Hydroforming is also used to produce complex, asymmetric tubular shapes. It starts with a tube that’s already been formed, making it a supplementary technique that can be used to make a simple shape more complex. Hydroforming fills the tube with water so that the pressure causes the metal to conform to a mold. The mold press may also be used to supply additional external pressure. 

Since metal can only be expanded so far, hydroforming is not suitable for all jobs. However, when performed by an expert metal manufacturer, hydroforming can produce lightweight, complex parts with seamless aesthetics that would be impossible to cost-effectively reproduce using traditional forming methods.

Other benefits of this metalforming process include:

  • Flexible design and engineering options
  • Superior bending strength and torsional stiffness
  • Increased weight and part reduction opportunities
  • High stiffness to weight ratio at low per unit costs
  • Thin wall tubing capabilities with Class-A finishes

Aluminum Extrusions

Extrusions are used to create aluminum parts that have a specific cross-sectional profile. The aluminum is pushed through the die to create the complex cross-section. Aluminum extrusions are lightweight and take on different colors and finishes very well. However, the complex nature of the shapes aren’t necessary for all metalforming jobs, and if a metal other than aluminum is needed, extrusions might not be appropriate.

A true, turnkey partner can take dull, straight extrusions and transform them into value-added parts. From CNC machine milling to automated sanding and deburring, your extrusions can actually deliver ROI with the right metalforming process and finishing expertise applied.

New value-added parts may include:

  • Automotive trim and exhaust pipes
  • Bath towel and rack components
  • Oven and kitchen cabinet trim
  • Commercial door components
  • Elevator handle parts


Metal machining takes a raw piece of metal and cuts it into the final shape and size via a controlled material-removal process. While it does allow for certain complex metal shapes to be created, machining simply can’t be used to bore curvilinear holes through metal, limiting machining tube production to straight shafts only.

However, full-service metal manufacturers can apply cost-effective metal machining options to work with your project’s specific design specifications. If your manufacturing partner has this machining capability and assembly expertise under one roof, they can even build machines in-house to fulfill your specific part need. This can reduce tooling time and money that would otherwise be spent on outsourcing this capability.

How to Choose the Metalforming Process that Meets Your Part’s Specific Requirements

At Mills Products, we can help you avoid excessive material handling cost, design mishaps, costly do-overs, wasted man hours, and production delays.  We begin by assessing the project, and our metal engineer and the design team team will want to understand how the part will function in the complete system. They can look for enhancement opportunities to improve the overall value of your final assembly. The metal engineer will ask plenty of questions to see if more functionality can be added to the part that didn’t exist before.

If the process isn’t immediately apparent, we first consider whether to hydroform or stamp it, typically looking at hydroforming first. We take into account the materials, the expansion ratio, the pressure to form the part, and the tonnage pressure to keep the part down. If hydroforming seems to be a good fit, we’ll put together a quote.

If hydroforming isn’t the best choice, then we look at stamping instead. If the volume of the production run is high, stamping is usually a good choice based on the economics. If stamping doesn’t fit the bill, we’ll investigate extrusions, machining, and other metalforming and machining alternatives as needed.

Even a “basic” design may not necessarily have a basic metalforming process, whether you settle on hydroforming, tube stamping, or roll forming. A turnkey manufacturing partner like Mills Products will have the in-house development resources to assess the necessary processes and tools to achieve the desired project outcome.

If you have a metalforming project you’d like to get a quote for, please contact us today.