Pushing The Limits

What can be done to exceed the limits of nonmandrel bending?

One possibilityy may be to reengineer for a harder material. However, this may not be an option.

Another option is to consider controlled wrinkles on the inside radius of the bend (see Figure 2). These are effective and could raise the feasible difficulty factor to more than 40, but the wrinkles also need to be acceptable to the finished product.

Another possibility might be to employ a shaped tube groove with a properly-sized plug mandrel. This is clearly a compromise, but may allow the elimination of a ball mandrel in favor of a simpler operation.

The most important factor affecting the limits of nonmandrel bending is the user's persistence to find better and faster ways to bend tubes. Today's limits are in place because of a driving force to improve.