Making Roll Forming Work for You

July 1, 2000
Choosing the right supplier for roll-formed parts such as side posts, roof bows, and scuff plate would seem to be a cut-and-dried process. Generally,

Choosing the right supplier for roll-formed parts such as side posts, roof bows, and scuff plate would seem to be a cut-and-dried process. Generally, the OEM provides the specifics for a trailer part, negotiates its best deal with the supplier and awaits the finished product. In many cases, the maturity of the trailer market tends to simplify the purchasing process because many tooled parts have been in production for a number of years.

But a new or revised roll-formed requirement completely changes the situation. Product design and tooling specifications must be determined. Product pricing, availability, and quality (always major considerations for any product) become even more important during the start-up phase of a new part requirement.

Technological advances such as e-mail and CAD file sharing have enabled the supplier to play more of a partnership role with the OEM's design engineers, but that can be a double-edged sword if the supplier and customer engineers haven't worked out, in advance, potentially sensitive issues of design and control. Clearly, some form of roadmap is necessary for the trailer industry OEM who is accustomed to dealing with mature designs only to find himself in a new environment.

Here are some things for trailer OEMs to consider regarding custom roll-formed parts. They are not listed in order of importance, because we believe that all of these points must be considered in evaluating a successful relationship between supplier and customer.

Product Drawing One of the first necessities is a product drawing, which will be used to generate a quotation. Thedrawing should detail all tolerances, critical to quality dimensions (CTQs), and raw material specifications. Special material grades should be noted as well as minimum yield and tensile requirements.

Another consideration should be whether existing parts can satisfy the current requirement or if a new design is warranted. Getting a custom roll former involved with the design-even in the modification of existing parts-may be to the OEM's benefit. For example, one of our customers had been purchasing steel blanks, press braking a cutout into the blank and forming it into a channel with mitered end cuts. Hynes converted it to a roll-formed shape with slightly modified mitered cuts and was able to produce it in one continuous operation. Secondary punching and forming operations were eliminated. The result-the new roll-formed shape reduced the customer's acquisition cost, inventory, and work in process.

Other obvious considerations that bear mention here are length tolerances and volumes. Both impact the final price of the roll-formed part.

Regardless of the size or cost of the order, one of the most crucial questions is always: "How soon can I get it?" The answer comes with understanding of material availability, in particular, knowledge of the supply chains. Delays due to lack of materials are becoming all too frequent. Is the roll former able to meet the growing demand of just-in-time deliveries?

How easily can the roll former trace material back to the producing source? Hynes has a service center that works closely with the producing steel mill regarding material consistency for gauge, hardness, yield, and tensile strength. A service center can streamline material flow directly from the producing mill to the buyers of roll-formed products, eliminating unnecessary handling costs and contributing to on-time deliveries.

Another benefit resulting from the service center/steel producer relationship is that even during a tight steel market, material availability isn't compromised.

Pricing Contract To "lock in" a firm acquisition cost and eliminate the ebb and flow of raw material price fluctuations, consider a 12-month pricing contract. This stability eliminates any purchased price variance (PPV) during the term of the contract.

The job of the custom roll former is as advisor, not supervisor. Custom roll formers should be more than willing to get involved, but only at an appropriate time that must be dictated by the customer.

Expertise is available for existing part applications as well as new designs. This means that the design can be modified into a more producible (which often means more economical) part. The greater the custom roll former understands the part, the better we can establish the manufacturing process to accommodate the trailer OEM's current and future needs. A custom roll former enjoys getting involved upstream during the product design stage to partner with the trailer OEM and design the most functional, cost-effective part possible.

A major consideration for roll-formed parts is getting the holes right the first time. Several state-of-the-art systems are available for hole positioning for the custom roll-formed trailer part.

They include: * Servo feeding and batch count control. This system enables the punch press to feed various lengths. Batch counting is a process in which the feed lengths are memorized in a non-regular pattern. The system contains memory for several part variations, which expedites part changeovers. Holes and slots can be positioned exactly where the OEM requires. * Servo feed output programming for punch gagging. This is still an effective system even though its technology has been around for several years. A die is built with the ability to call in or out several different punches on a program. This means that the die will have multiple punches instead of a single punch. It's extremely cost effective to install holes and slots during the roll forming process rather than in a secondary operation. * Automatic feeding systems and parts positioning sensors. Rivet holes must align exactly with the OEM's prepunched side panels during assembly. These sensors ensure that parts are located properly during punching operations. Holes are positioned +/- .005" end-to-end "non-accumulative" for standard side posts. Hynes has been able to use this system effectively to bolster its "zero defects" quality efforts.

Smart tooling, the use of sensors and photo optics, should be employed as much as possible to reduce the risk of error. It should be an integral part of the manufacturing process with the goal of eliminating defects and their costs generated by poor process control.

It's advantageous for the roll former to be capable of punching holes and slots for parts such as side posts. That capability enables the custom roll former to supply a finished part to the customer who, otherwise, would likely perform additional secondary operations in-house. Generally, customers will find this a cost-savings value.

Other Factors Other matters to be considered in choosing a custom roll former include ISO 9002 certification, available equipment, financial stability, sales and engineering support, location and the supplier's history of reliability, and service that can never be downplayed.

E-commerce will also assume a greater role in the ordering of trailer parts, especially existing ones. All of those elements ensure that companies will still want, no doubt demand, continuing direct relationships with their suppliers. But high quality workmanship and competitive pricing will always be prominent in the purchasing process.

Mike Giambattista is the general manager of the Roll Formed Products Division of Hynes Industries, Youngstown, Ohio. A custom roll former with more than 60 years of experience, the company has 30 roll forming lines, three slitters, a stocking program for JIT delivery, and a service center containing 28,000,000 lb of steel on site. The company custom roll forms shapes from 30,000 to 80,000 psi yield strength and in thickness from .010 inches through .250 inches.

About the Author

Mike Giambattista General Manager