7 ROLL FORMING DESIGN FLAWS TO AVOID

As with all manufacturing processes, careful design of your component impacts your overall costs, lead times, and quality performance. Follow these tips to avoid the common pitfalls of designing custom roll form parts.

Now, we know some components require difficult or non-standard manufacturing work, so you may not be able to follow all of these rules. But by removing as many hurdles as possible in the design phase, you can reduce up-front costs, maintain part functionality, and improve manufacturing consistency.

ROLL FORMING DESIGN: 7 FLAWS TO AVOID

Roll form design can go off the tracks quickly if your concept involves one or more of these features:

Small bend radii

Extremely short flanges

Wide, curved shapes

Blind corners

Narrow openings

Deep, vertical sections

Wide shapes with an un-formed

While each one of these can be a problem, there are ways to mitigate them all.

1.  Small Bend Radii

The Problem: Tight corners can cause cracking in heavy-gauge, galvanized, or pre-painted materials due to stresses generated on the outer fibers of the bend. They also increase tool wear and breakage, and require a mill with greater horsepower (all of which affect your costs).

The Fix: Allow for a minimum radius of 1.5 to 2x the material thickness for best results. Or, consider whether a more ductile material can be used to produce your component.

2.  Extremely Short Flanges

The Problem: Short legs can be impossible to form in heavier gauge materials.

The Fix: Allow for at least 3x the material gauge as a minimum flange length. Longer legs provide more leverage to bend heavier materials.

3.  Wide, Curved Features

The Problem: Since a sweeping bend (think half-pipe) may not stress the material beyond its yield point, it can be a difficult shape to control and is more prone to springback.

The Fix: Design for flat sections with discrete bends to reduce roll forming tool design costs and initial setup scrap. Or, consider a material with lower yield strength to ensure that curve holds.

4.  Blind Corners

The Problem: Also called “air bends,” blind corners occur when the roll forming dies cannot contact both the inside and the outside of a formed corner. These bends are less accurate and more difficult to control throughout the forming process.

The Fix: Design your component to avoid this situation completely -- make sure the part will be in contact with inside and outside rollers at all times.

5.  Narrow Openings

The Problem: Narrow openings (in relation to the overall size of shape) make designing cutoff tooling extremely difficult. They can also result in frequent roll die maintenance and cutoff die breakage.

The Fix: When designing your part, allow for more than half of the section width for your opening.

6.  Deep, Vertical Sections

The Problem: These designs require large-diameter forming dies, which increases the cost of tooling. These components might also be "partially" formed via roll forming, then finished in a brake-press as a secondary operation.

The Fix: Make the flat section wider, or open the sidewalls at an angle. If you absolutely require a deep, narrow channel, ask about MeshTrim.

7.  Wide Shapes with an Un-formed Edge

The Problem: These parts are unbalanced and incredibly difficult to keep from twisting or rippling.

The Fix: Add a small leg on the un-formed edge or introduce a stiffening rib for greater overall strength and consistent formability.

roll forming machine for sale

roofing sheets manufacturing machine price

double layer roofing sheet roll forming machine